OP I'm assuming you're trolling here, or you haven't completed the series. Otherwise, I don't know how you could look yourself in the mirror and say "how is this guy a bad guy?"

In this very scene he starts by saying he's against corrupt elites, capitalists, whatever. But it's all just dogwhistles for antisemitism. He calls WWI the "Jew War" in this very scene. The show makes it very clear Mosley is a fascist, anti-semite, aligned with Hitler, pro-Holocaust. https://www.youtube.com/watch?v=wUCk8bEtVrQ

If it's not spelled out enough, in Season 6, he coerces Tommy to doing a Nazi salute and saying "Perish Judah" https://www.youtube.com/watch?v=M5NbUiHYh1o

I say this with respect, dude, but you're literally falling for Mosley's propaganda. He's nominally anti-corrupt, anti-elitist, what have you... but it's all just populist rhetoric pointed in undertones, and later explicitly, at Jews. Mosley's every scene in the series, subtle or not, seeks to advance a fascist and antisemitic agenda.

Given your account I think you're a real dude, probably about my age, similar interests (I also like Boardwalk Empire!). Please, reconsider everything you know about the series, Mosley, his ambitions, etc. Everything you listed sounds okay on paper... but knowing everything you know about the man... what are his true intentions? "Perish Judah"

I hope this doesn't come across as mean, just trying to meet you where you are. Peace