I'm not saying he isn't unambiguously bad, at least in terms of events contemporaneous. I'm saying that the main characters in Bebop exhibit moral ambiguity, even (and especially!) if they eventually do the morally right thing from the viewer's perspective. Their journey towards the right thing is, after all, what makes them interesting to us; Bebop would be a lot less interesting if the characters didn't struggle with their histories, impulses, &c.

(Another example of moral ambiguity I just remembered: Spike's personality and design are an explicit reference to Lupin III, the platonic anime anti-hero.)

> Most of the people with bounties are actually doing bad things, and bounty hunting itself isn't illegal in the setting.

Illegal is one thing, and morally ambiguous is another: being a bounty hunter is perfectly legal in the US, but I think most people would consider it a morally ambiguous job.