When your failures in life are attributed to something other than your bad decisions/choices.
Something inherent, something that you are born with that hinders your ability to function properly in society, lead a normal and fullfilling life, attract a partner etc.
Typically men are affected more severely by this than woman (according to statistics)
Person 1: ... but how come you never dated
Person 2: I can't, I'm an incel, stuck forever inside my genetic prison