I respectfully disagree. While I generally post under my legal name (including all of my Hive, Medium, and Twitter content), I see no moral nor ethical problems with posting anonymously, especially when speaking truth to power. (For the purposes of this comment, I'm not concerned, nor am I sympathetic to, speech that is intended merely to hurt other people in any way, even though I also believe that there's no such thing as the right to not be offended.)
I used to think otherwise, and believed in the nobility of posting exclusively under my legal identity. But then I realized that with Big Tech (Facebook, Google, etc.), our legal identities, and the data we generate by being online or even just carrying smartphones around, are commodities to be sold to the highest bidder, and offered up to government and industry for endless analysis and exploitation.
Besides jail, there are also civil actions that can arise from expressing oneself, even if there's no legal merit to such actions. Where litigation is concerned, whoever spends the most on lawyers wins.
Even if there are no legal consequences, there is always the threat of reputational ruin or some other form of collateral damage, for merely holding an unfashionable political view.
And so, in this day and age where powerful interests want to control our speech, anonymity can be a form of protection for saying what needs to be said without fear of unjust persecution. Otherwise, our legal identities are often something that can be used against us to keep us under control.
As I said “unless it’s something you can go to jail for”. What I hate about the internet are the vicious attacks anonymous people usually use against other people (famous or regular people), attacks they wouldn’t dare using otherwise...
I think we're somewhat on the same page. I try not to go anywhere near my keyboard if I'm feeling riled up about something or someone--otherwise, I end up posting something I regret, and it never ends up being high-quality content on my part.