* Many tech pioneers and leaders deep down felt an animosity towards supporting people who didn't fit the mold and finally feel free to express it (the worst-case outcome), and/or
* Many tech pioneers and leaders wish to continue supporting those who don't fit the mold but feel their own status threatened by figures with nearly infinite power[0] who disagree.
The former are simply the intolerant coming up for air. The latter exhibit a cowardice, though there's a subpoint to that second bullet: there could be some in this crowd who prefer to conform to but then dismantle the power structures enabling hatred from within, but these people likely won't be known for a while, and it'll be difficult to predict who's acting subversively in this way. Though given PG's narrowly scoped essay, there's a reasonable chance that this is his footing.
The best people can do is assume the least-worst case - the cowardice - and instead seek to either craft themselves as the people they wish to see... and/or protect oneself from the rising tides of hatred.
[0] https://www.supremecourt.gov/opinions/23pdf/23-939_e2pg.pdf