Facebook tried this, and it did not go well for many good reasons. But also, inasmuch as people are tied to their real identities on Facebook, your first liste

Facebook tried this, and it did not go well for many good reasons. But also, inasmuch as people are tied to their real identities on Facebook, your first listed advantage doesn't seem to hold up. On many websites, I see people using their real names for trolling and extremism, saying outlandish things pretty frequently. Any political post on fivethirtyeight.com should serve as but one example. Not everybody values their online reputation as much as you might. Many people think nothing of using their real name to heap scorn on and revile people they consider "others," like those of a given political party or ethnicity or religion. I know PennyArcade once hypothesized that anonymity was key to greater internet nastiness, but it doesn't seem like anonymity is actually that essential. On the other hand, many people rely on pseudo-anonymity to avoid harassment, to shield themselves from stalkers such as ex-partners, and so on. Many people lack the sort of legal documentation such a policy would seem to require. Trying to enforce anything like "RealID" results in excluding many voices from the conversation, while not actually doing much to reduce the toxicity.