If this was a Marvel Studios movie, fanboys would love it. It's that simple really.
It has too much plot, and an unwieldy structure, sure; it also has some misjudged comedy moments. But it has a great Spider-Man, a great cast, genuine emotion, a wonderful score, and fantastic and huge scale action scenes. Jamie Foxx is great a Electro if you overlook the goofy loser cliches he exhibits early on. Dane Dehaan is both sympathetic and menacing, and you really feel for him as he gets trapped by his fate.
In ten years or so, when the Marvel Studios fervour has died down, fanboys will re-evaluate the series and give Amazing 2 more credit.