You don't have that much stuff to grind in vanilla, and all grinds can be circumvented by enough gold. The worst grind I did while playing on Kronos was for Cenarion Hold, and I didn't participate in 95% of it since everyone was doing it and I just alt-tab sat in a raid group while others were killing shit. I did it to get the Priest healing weapon from AQ20. And I think it was kinda pointless in the end because AQ20 gives ridiculous amounts of rep per run. Apart from rank 14, the other grotesque grind is the bug parts for the scepter quest, which I wouldn't touch with a 10 foot pole. Other than that, even if you grind for everything, like consumables and rep, it isn't THAT bad, in the sense that it doesn't take obscene amounts of time. A few guildies of mine managed to get exalted with ZG the day it was released.
It's true that GW1 is (was) a better MMO and EQ a better RPG than WoW, though. EQ has too much grinding and GW1 is dead. So much for that.
The combat is a more complicated matter. The main attraction of it is that WoW has good "kinaesthetics", i.e. it's smooth to play, like all other Blizz games. Even though you do go through the same motions while leveling, it somehow doesn't get so repetitive that it gets boring. At least combined with the different quests and zones + dungeons here and there. I really have no explanation as to why, apart from that it's responsive. When I've tried to psychoanalyze myself on this matter, since I'm allergic to repetitiveness, I've found out that WoW strikes a peculiar cocktail in which every ingredient feeds into the others. When in a given moment the combat is repetitive, the accumulation of items makes up for that, when both of those dry up, the social aspect (if you are into that sort of thing) brings you back, then inevitably comes the new content, so you have something new to do, then you have the AH minigame where you try to squeeze as much gold from the market as possible. It's a psychological trap in other words, but not in a malicious way. Vanilla is not designed to be like those Korean MMOs where easily addicted personalities are caught in a loop.
You can't have PvP without balance, at least some semblance of balance. Like in many games, Blizzard inevitably fell into symmetric balancing that ruined PvP forever. Every healer must have a dispel, every DPS an interrupt, everyone a stun, etc. This is not only boring and makes the classes pointless, it's also basically impossible unless the classes are perfectly symmetrical and have the exact same abilities, because even small inequalities are immediately felt at least by the top players and FOTM classes/comps pop up. It's better to have hardcounters up to a point than to give all abilities to all classes, but it should be taken care to not have 1 comp that hardcounters everyone else, like Warrior/Druid in TBC or Paladin/Death Knight in WotLK. 3s were better in this regard, though, and that's why 2s were excluded from titles. Different categories were probably a mistake, only 3s should've existed in the first place. My point is that balance is important, but the attempt at symmetrical balance is dooming.
As I've said before, vanilla's problems (economy, raid schedules, guild politics, raid mechanics, rank 14 grind, lack of meaningful PvP) can only be felt by the top players, so it's not surprising that many people aren't affected and are excited to play it again.
