It leads you around the whole map to do so, so you get introduced to the world - I can't see it as different to FO1/2/3, which also let you be really single-minded about your goal if you want. You have plenty of reasons to explore before the Strip: helping people in the towns who are helping you; being cautious about Benny, who you've found out has already killed one of the people who helped to kill you; doubling back to get Cass; and then mechanically: getting enough caps or the King's favour or whatever so you can actually get in.
The way that it guides you through Primm, Nipton and Novac was criticised quite a bit back in the day, I seem to remember. In Fo1 you're directed to Shady Sands but beyond that you could wind up anywhere, in Fo2 you don't really have any goal other than Vic, who himself is a bit useless when you finally meet him. In Fallout 3 you've got no real information at all at the start and, while the game does offer one solution via the Moriarty-GNR-Rivet City thing, you can end up bypassing that entirely and finding Dad by accident, or skipping GNR and going straight to Rivet City (or you can even just listen to the radio, where you can overhear that Dad has gone to the Rivet City area).
New Vegas basically offers you two routes - do what everyone's telling you to do and circle through the south of the map, or just decide that you're going to walk directly to the big lights that you can see in the distance, in which case the game throws a bunch of beefgates up in a desperate attempt to get you to turn back.
Yeah, a Mojave Express courier who travels through dangerous lands delivering messages and items and picking them up. House has a reason to invite you in (Benny, whatever you have or haven't done with him at that point), everyone has a reason to take notice of that, and then I guess you could say "no, I'd rather go back to delivering packages", but why would you? The danger? You were already getting murdered, but at least you're getting paid better now. It's a very specific kind of character that would instead say "this is too scary, I'm going back to NCR". But it leaves you plenty of room to decide why your Courier does exactly what they do (and if you really like the 'because your dad/Overseer/Elder told you to', you can apply that to House)
This is fair, but it still feels more awkward than the other games to me - in Fallout 1 and 2 the lives of everyone you've ever known are directly under threat, which is a decent enough motivation for 95% of characters. In Fallout 3 looking for Dad is a decent enough motivation for the first half (and the game lets you play it as though you're finding him to interrogate him about his idiocy, rather than finding him simply because he's Dad), and the second half is much much shakier - not least because nothing that's happening by that point makes sense - but trying to start the purifier is just good sense, especially since you've been exiled from the vault by that point so you'll have to live next to the shitty irradiated river forever.
But the only real motivation the Courier has is being a mercenary. And your backstory indicates that you're that way inclined, sure, but it's also suggested that you're a wanderer who drifts around a lot, and suddenly becoming a major political figure just feels jarring to me. It's also far more responsibility than you get in the other games - Fallout 1 is entirely about saving the Vault, even when you're seeking Mariposa. Fallout 2 is entirely about saving the village, you only end up on the Oil Rig because the Encalve give you no choice. Fallout 3 is about trying to start the purifier (and, inexplicably, getting mad when the Enclave try to do just that), with the player being one part of a larger team. But New Vegas suddenly makes you into, probably, the single most important and influential person in the Mojave, in a way that has nothing really to do with your initial motivation to set out into the Wasteland, and relies on all the factions acting in pretty bizarre ways towards you.
At that point to Courier should became clear that a major local conflict is coming very soon so picking a side makes sense, after all there's no option to entirely fuck off. And to the writer's credit, all main factions are translating various perks of working for them just right about now (to a lesser extent, Caesar perhaps but my memory is hazy here). This is all approximately a million times better than FO3's prot motivation imo.
I dunno, I don't feel like anyone offers a really significant motivation to work for them, nor does it make a great deal of sense that anyone's trusting you with all this. So, like, presumably House's initial plan was to have Benny go to the Fort and activate the Platinum Chip. So Benny betrays him, and he... trusts the mailman instead? Someone who just walked into the room, who he knows nothing about, who his only connection to is that they were hired by some third party postal service?
Caesar trusting you
after you've wiped out Nelson and killed two hundred Legionaries is absurd too - I get why they do it, it's because many players would find it annoying to be locked out of major content for their early-game decisions, but it still looks absurd. You killed Vulpes, retook Nelson and beheaded Dead Sea, laid waste to the Legion assassin teams sent by Caesar himself to kill you, restored Camp Forlorn Hope and ensured the Legion would never regain their foothold in the area... but you were seen leaving The Tops, so Caesar has ordered that you get a full pardon and he reckons you'll be well up to work for him now.
The NCR has the same problem, combined with the fact it never makes much sense that they're trusting a random mercenary - who was a wandering mailman three days earlier - with state secrets and high-level stuff that should be going to their top agents and officers. And of course, House is then shocked when you - someone he knows almost nothing about, and who never showed any inclination of wanting to work for him - blows up the Securitron base rather than doing as he says. Caesar is similarly agog when you, someone who has killed every Legionary you've ever met, starts shooting after he invites you into his personal headquarters for an unarmed one-on-one chat.
It's weird, it feels like everyone in the game just gets the memo that you're the protagonist as soon as you exit The Tops, and start treating you accordingly and giving you all their secrets and inviting you to meet their leaders, even though you're an anonymous postal worker who has no reason to be part of any of this and has given no indication that you're trustworthy.
The Courier lives in the Mojave. Why do you think he has no interest in the political future of the region? Is he a sub-80 IQ nigger?
The Courier doesn't live in the Mojave, iirc. That's why for the entire early game s/he's wandering around asking people where shit is, to the point where on release, a lot of people came away with the misconception that the Courier has amnesia.
Your dialogue, on the rare occasion you get to express any kind of backstory, usually indicates that you came from California*. We also know that you went to Lonesome Road at some point and all that weird shit happened. Johnson Nash, the manager of the Mojave Express, also doesn't know who you are or recognise you - the Platinum Chip was presumably your first job with them. I'm absolutely certain that you come from outside the Mojave, and iirc the ending slides might indicate that you leave after the events of the game.
*though some of your dialogue can also indicate you don't quite know who the NCR are, in which case god only knows where you're from
