I just dont think Eccleston had any intention of doing more than one series, right from the off.
I'd also hazard a guess that he had to be persuaded to play The Doctor in the first place, as he likes to be seen as a "serious" actor. (although rumour has it he emailed Davis to be put on the list)

He's much the same as Chris Barrie from Red Dwarf IMO, in so far that he thought he was big enough to just walk away from the show, and jump into much bigger roles.
In fact, he has already admitted in interviews, that he was never a fan of Doctor Who, which once again sugests, he never really had any respect for the role, and just wanted something that might be able to further his career.

Unlike Barrie, he couldnt come crawling back when he ended up no better off than when he started.

As for the accent thing, I dont think its national pride, I think its just his inability to adapt to any non-northern roles.
I dont hate Eccleston, I just think some people put him on too much of a pedestal for his so called "acting" abilities!

Snarf is shit. His death will be rejoiced!