If they'd have done that to Jill, I'd have jumped ship. Seriously. Jill really is one of the most iconic heroes of Resident Evil and one of the most badass video game heroines out there. It'd be extremely lame for her to get a death like that. I think they did her well in this game, appearance aside. I'm not digging that blonde hair either. But I just chalk that up to Wesker's bad taste
But yeah, killing Jill off would be so lame and shit. So I think this is one of the things RE5 did right.
The revelation of Wesker's origin was...rather bizarre. That's the one plot revelation I could do without but whatever. It's not like it really changes much about him anyways. Just something I didn't really like.