While I typically agree with you, you're apparently waaaay too close to this material. It's not that the flaws you've pointed out are all untrue, it's just that they're not nearly as big as you've made them.
And as to "Who is Peter Parker?" this movie created a more authentic Parker than I've seen yet. Not all geeks are the same kind of geek. Not all smart kids are the antithesis of slackers. He had dimension, in that he had the kind of conflicting identity and motivations that real high school kids have. (I work with high school kids every day, and this one felt like a high school kid, particularly one with Peter's home situation)
THE BIG THING:
They can't continue to tell these stories to the original audience. They can't continue to pay the ever-increasing tribute to the "core fans." Superman, Batman, Spider-Man, these are characters that, to a degree, have outlived their audiences. What other medium does this but comics? (And, to a lesser-but-analogous degree, James Bond movies. Much-needed reboot, because the social climate is very different from when the first movies were made.)
Trying to keep the same character alive and fresh and interesting, and staying roughly the same age, and yet still appeasing to the "loyal fans," is the entire reason comics develop the twisted, knotted continuity and insane escalation that you've so often decried in your COMICS ARE WEIRD pieces on The Big Picture. Stories need endings to keep from getting this outlandish, and it's not always wrong to re-tell them a little differently after that ending.
With a lot of these reboots, there is a recognition that the characters are outliving their original audience (or at least their attention span). They're maintaining connections to the original, in hopes of bringing some of the old fans forward, but they're mostly trying to bring in new fans.
The problem when some folks get a little too "invested" in a particular version of a character, dating back even to childhood, is that those people begin to feel like investors. That is to say, they feel they're entitled to a particular return on that investment. And when it doesn't pay off that way, they get angry.
Batman. The whole DC universe. The heroes of the Avengers. Spider-Man. James Bond. They've all recently gotten reboots. And is there a huge financial motivation? Sure there is! You've got at least a somewhat guaranteed audience over trying to create an entirely new character. But also, there is a love that audiences and writers have over the core concepts of these characters... but not always over the insane continuity stretching behind them, or some of the archaic stylistic elements.
I feel that, in the majority of these reboots, that core concept has been retained and perhaps refined a bit. Some details are changed to avoid a super-strict retelling, and some characters are recycled for familiarity reasons, but the character is preserved. This movie is no exception: this felt more like a Spider-Man movie to me than any of the Sam Raimi projects (which, don't get me wrong, I still enjoyed).