[fancybouncy]

> have let themselves go and have nothing "going for them"

that is, they fell ill with depression because of lack of relationships, entering a loop of ever-furthering isolation and depression, which made them bitter and undesirable.

Some "ugly, socially awkward nerds" somehow find meaningful relationships and get saved. Others don't, and go down the nasty road.

A little bit of empathy wouldn't hurt.