Now that Trump doesn't serve any value to Twitter or Facebook the bans come. Before they justified his behavior because he brought them viewers. It may be cynical but too convenient to play the morality card now.
If you're a multi-millionare choosing dollars over ethics, you are in the wrong. Plain, clear, and simple. And I hope every tech-leader who has profited from this dumpster fire is labeled in history as such.
All that being said: Until November of this year, he wasn't "just Donald Trump" - he was the PUSA. There's a very big difference between banning PUSA and banning DJT. Now if you want to argue they should've done this the day that the results were in back in late November - sure. But the previous 4 years? I'm not sure that was a path either company was willing to test and I can't entirely blame them.
Also: Trump serves them no value? Are you crazy? The viewers haven't gone down, and won't go down in any significant manner. For all the bluster from right-wingers of "we're making our own social network" - they all still somehow seem to be participating on both platforms.