So, apparently Xander from Buffy is today's preeminent SI for fanboys to insert themselves into, get powered up six ways to Sunday, go on a multiversal jaunt, end up with a harem, and take out their aggression at any other characters they don't happen to like. Yeah, I get that. All the way back since Ranma was pretty much the same thing for anime fanfic authors.
It doesn't stop me from bristling at the latest soapbox ranting of the sockpuppet author when I was skimming through a BVS/Girl Genius/DCAU xover that is just rehash of the old rant about how superheroes with a moral code are somehow responsible for the actions of their rogues. Heck, it's not like the same issue hasn't been raised in thecomics themselves. But alas, I've rarely seen the argument actually written out well without handing the idiot-ball to one side of the argument and the jerk-ball to the other. Ironically, the comments to that second scans_daily link contains far more insightful arguments toward both sides of the issue. Of course, the first link was a sort of good try for the comics writers, but of course that was back in the days when superhero comics were still run out of newspaper strips. (Oh how the "art" of comics have degraded to these sensationalism-is-all days. :P)
Anyway, personally, I've never bought the whole idea that the superheroes are responsible for their villains thing. It always smacked of the whole 'shift the blame'/'blame the victims' line of thinking, and most attempts to argue it in the stories nowadays appears to absolve the villain of their own culpability for the apparent goal of inducing wangst and emo for the hero, as well as justifying bad plot.
Secondly, I've never really felt that the role of executioner should fall on the shoulders of the heroes - at least, let me amend that, for foes in a civilized setting that are capable of being executed/locked up by mundane means and methods. Uber-powered bad guys that want to blow up the planet or something...Yeah - if the hero is the ONLY one with the capability to end the threat (and especially imminent future threats) to the public/humanity/Earth, they should shoulder the responsibility of terminating said threat. But for the likes of Joker and such, I would expect the responsibility to rest where it has always been - with the legislature (if exceptions need to be made in the death penalty laws of the state) or with the courts (if death penalty is already legal). Blaming the hero in that case seems to be a scapegoat for the public to avoid their own implicit culpability for these villains, which is not any less than the heroes in these cases.
And the thing bugs me the most in certain fics... is the way that some authors look down on various superheroes for having and sticking to a moral code. I mean, I don't get it. Why would you WANT people with superpowers or means beyond normal men to NOT have a moral code? To have a flexible moral code that can be bent when the fancy strikes them or whoever can manipulate them? I really, really don't get it.