Indeed, as evidenced by the overwhelmingly positive response to Charles Deveaux based, as far as I can see, on nothing but his being nice towards Peter and complimentary about him. (And ignoring completely that Charles' passivity and not doing anything to stop the explosion for years is the same thing it has condemmed Nathan for when with Nathan it lasted a week; not to mention that Charles even does the Angela thing of leaving his own child completely in the dark and risking her death.)

There is also the fact that he doesn't believe the bomb is inevitable, but again, he could have said something. Or left a note. Anything. (I'm also not entirely fond of him encouraging a relationship between his daughter and an obviously unstable heroin addict, not least because I'm not sure that this wasn't because they needed Isaac's paintings.)

As for differing reactions re: Charles and Nathan virtually doing the same thing, it's mostly irrational. Partly it's because he is nice to Peter - witness how long it took a lot of fans to accept that Angela was not a nice old lady, and how difficult it is for most of the audience now to allow that she might indeed love him, while she never once gave the impression that she felt anything for Nathan as a person, and nobody objected to that until Claire was concerned, and after that still interpreted it as okay until she really came close to almost coercing him into going along with her. Much as I love Angela, I find her emotional treatment of Nathan horrible to put it mildly, and I'm really taken aback that the majority of fandom mostly shrugs it off with an "Oh well, Nathan's a jerk, who cares." I think judging Nathan's behaviour worse than Charles's partly goes in that direction - Nathan is bad, because he is not always nice to Peter, so he gets cut much less slack - but it's also because he is an important character, and we have three other important characters who expect him to do the right thing, so why doesn't he do it already. (There is also a somewhat negative effect of the show's pacing - Nathan may have only hesitated for a week, but in real time, he hesitated almost four episodes and one what if situation, which does translate to around five weeks where the character is basically treating water.)

I'm oddly reminded of fannish reaction to the Spike/Buffy pairing; [...]and guess whom a lot of fans felt protective about?

Ahhh, the evil spectre of Spuffy. Begone, evil, begone! (I was a lurker during Buffy Season 6 and 7. That was a truly eye-opening experience.)

Spike love is still a mystery to me, mostly because I liked the character exclusively in Season 2, now and then in Season 4 and 5, and in Angel Season 5 (for the latter I might totally be the only one). I think he is like Peter in so far as he also seems to present some sort of romantic ideal, and inhabiting the traditionally feminine role plays into that as well, since who doesn't want the guy who is emotionally open enough to understand how you feel? (At least I have heard that this is the case for a lot of straight girls. Not that I am too familiar with the situation; needless to say that if I was more romantically inclined towards guys, my ideal would probably be ... Charles Bingley? At least he is funny!)