I think there's merit to say that, while he may not have plotted to kill an entire CBI team unless Jane had pushed him, he was still a bad man from the beginning, and a villain at that point too.

While the California legal system might not have been able to convict him of any specific act of pedophilias/sexual abuse of a minor, he still in some part acted on those urges. At the very least, consumption of child pornography, and at the very worst it would be, probably kidnapping, sexual assault against a minor, which he at the very least photographed (so the creation and possible distribution of CP) and possibly recorded, probably killed (look at the way the legs and arms are facing in the picture Grace takes down in s4e7 at timestamp 29:18), and then tried to conceal from the police who had a warrant to search his home.

While we as a society recognize vigilantism as bad as one person cannot and should not be judge jury and executioner, we at the very least CAN look at someone morally and say that they're a bad, malicious, or evil person because of the actions that they take, with or without finding them 100% guilty within the eyes of the law. The law does not govern morality, or else people that cheat on their spouse (a generally immoral thing to do) would spend more time in prison than someone who was solely in possession of recreational drugs (something that is really not moral or immoral).

While Richard Haibach might have a legitimate sickness stemming from his abusive home life, coupled with some serious mental disorders/issues these in no way excuse his actions, and he should have gotten help for them before they reached this point. Anyone, regardless of whether or not they're found guilty, or have developmental/trauma issues, who sexually exploits a minor, yes even through just the consumption of CP, is a villain through and through.

The fact that he attacked Jane's team, even out of vengeance is irrelevant.