There is no way they could have held a second primary in the 28 days between Biden dropping out and the DNC. Polls said Democrats wanted Biden to drop out, Democrats had already elected Harris once, and polls said Democrats were happy with Harris as the nominee. That's about as democratic as you could get given the situation.

Criticizing the Democrats for being anti-democratic here would carry a lot more weight if the Republican nominee wasn't responsible for J6 and the fake electors plot.