The alternative to Biden will be Trump. He doesn’t have anyone’s interest in his mind but his own. A vote against Biden is a vote for Trump, unfortunately.
I don't know why you are getting down voted, this is very true - however, in a primary, vote for who you want. Then in general - vote for Biden because that will be the only sane nominee in the ballot.
Scolding people and blaming them for taking a moral stand is a losing strategy. Change strategy or accept that you are contributing to Trumps election.