I don't see how a dud of a movie ruins the other ones that came before it, especially if you liked them/him before 2007. It just doesn't make sense. He was a good, every day, awkward kid learning about responsibility in the first one. In the second one the responsibility is straining him emotionally, physically and financially. I don't see what Maguire did wrong. Yeah, nobody likes Emo Spidey (I don't see why they like Hipster ASM either) who dances in 70s fashion acts like a weirdo, but before that, there was nothing wrong.
TDKR felt stupid and lame to me, I didn't like it, but it doesn't make me view Batman Begins and The Dark Knight any differently. I still love them.
Terminator 3 is crap, Arnold as the T-850 was obnoxious. T4 was bad too. Doesn't mean that takes away from Terminator and Terminator 2, or that Arnold sucks in it.
Same with Star Wars.
Tobey Maguire wasn't dancing or strutting or looking emo in Spider-Man 1 and 2. I don't remember any complaints about him in those first two films when they came out or until after Spider-Man 3 and this whole ASM thing.
Hell, I remember back when Spider-Man 2 was in pre-production and Maguire hurt his back and wasn't sure if he'd return everyone seemed to be afraid that they were going to recast him with Jake Gyllenhaal.
So a douchey, skateboarding, hipster bro Peter with fingerless gloves and no respect (doesn't even respect the dying last words of his girlfriend's father) is cool, but a a douchey, strutting, emo Peter who wears all black and has no respect is fine?
I don't get that one.