People don't like the idea of things being outside of their control especially since we're raised on the ethos that if you work hard enough you can change whatever unfortunate circumstances you've been dealt by the random game of genetics like it's a bad school grade or something.
They like the idea that their loneliness is only temporary and if they wanted to, they could fix it.
The Blackpill essentially takes away that light at the end of the tunnel we've been taught to believe in all our lives, causing most people to shut down and go into denial that their subhumannity is forever and they won't ever get their Happily Ever After you see in Disney Movies, condemning them to a life of a lonely spectator.
That absence of hope gives rise to depression. As a final defence mechanism people will often reach out to others and ask if they're ugly with the hope of being fed cope that they're not and whatever perceived unattractiveness they may have is due to something they can change like a bad haircut or bad clothes.
Even Looksmaxing is a last ditch all out effort to ascend to save yourself from falling into that gaping pit of eternal loneliness and depression