Enough people doing that would have the predictable result of getting Trump elected,
I agree with this and it’s what I’m afraid of. I totally support voting in the primary as you wish, even just to send a message (I support voting how you wish in all cases). But in this case using primary voting to send a dissatisfied message about the Democratic candidate has me worried it will instead send a wider message (or mass media will push this message) that the US populace feels Biden is unpopular compared to Trump.
Which is absolutely not the case with the vast majority of people voting against Biden in the primary. But that kind of message (accidental or intentional) can do real harm to prevent a literal fascist takeover in November. This is the totality of my concern and if we weren’t facing down the potential end of democracy in the US, I’d give a lot less shits about potentially torpedoing Biden’s chances. And I feel a lot of the hate against Biden has galvanized right around the time the primary season started which seems convenient for Trump.