Re: Ignoring Superman 3 and 4
It was a bad idea because Singer therefore muddled the exact sequel his film uses as a springboard for its own narrative purposes. The film suffered from cherry picking elements of Superman 2 and discarding others, leading to a lot of confusion over exactly which film it was a sequel to, Superman or Superman 2. Singer should've ditched his film's connection to Donner wholesale or he should've taken all the films into continuity.
Alan Moore on comics:
They've lost a lot of their original innocence, and they can't get that back. And, they're stuck, it seems, in this kind of depressive ghetto of grimness and psychosis. I'm not too proud of being the author of that regrettable trend.