The big problem with KotOR II's starting area was that it was just too long. If it was say, 3/4 of the length but hit all the plot points, I'd be totally fine. There's just a bit too much backtracking and whatnot that drag it down. However, the conversation with HK-51 and the miniature mystery plot that forms when you're going through it is really cool, especially the first time.
The tutorial level and Taris in the first game, by comparison, were absolutely horrendous. Taris and its undercity felt like something that should be in a goddamn Forgotten Realms game, and contrivance of the plot points gets really silly - so we have to go through the undercity and deal with a tribe of exiles in order to get a key that will let us go into the sewers, eventually bringing us into a gang's home base, where we can kill all of them and steal their prototype podrace parts, and then go win a podrace against them even though we just killed them all and looted their base, so that we can rescue someone who breaks out without our help anyway? This shit is worse than The Phantom Menace. The complete and utter lack of disconnect between the actual objective and the places the story takes the player is shocking.
Of course, the rest of the game isn't much better. Your goal on all the other planets is to find the Star Map, right? So you've got all this shit like the Wookiee slavery, the Imperial embassy and submarine base on Manaan, etc. but why do we have to do all this shit in advance? The vast majority of plot points at that point in the game should be completely negated by the fact that you are a goddamn Jedi and have a lightsabre. Why the fuck do you have to run errands for the Rebels to get to their sub? Why not just walk past them and steal it, or cut through the door? Why do you have to do all this shit for the Wookiees to make a guard stand aside so you can use an elevator? The Krayt Dragon thing on Tattooine actually makes sense, because it's a goddamn Krayt Dragon, but then apparently "nuke it from orbit with the Ebon Hawk" never occurred to anyone. At least the Korriban Sith Academy makes sense to infiltrate, though you can kind of just hack your way through all the Sith just fine anyway, and the stupid quests you have to do to just reach the right tomb are pretty contrived. The only time the plot actually gets kind of interesting and makes some sense is when you go to the Star Forge and its planet, but by then it's too late.
I think that more than anything is the big problem in KotOR - it's written not like you're a godamn mythic Jedi knight, but like you're just some ordinary dude. Just about everything in the game should be negated or overridden by that fact, but instead the vast majority of your time is spent doing errands for NPCs and trying to get into Bastila's pants. The sequel was smart enough to acknowledge that Jedi are really damn powerful, so the plot is driven by goals (reach Goto's ship! find the lost Jedi Masters! reclaim the Ebon Hawk!) and not by "how many fetch quests do I have to do before someone lets me through a door?"