Generally is it their own fault when a guy can’t get a date?Watch
But there are lots of other possible explanations too: they might be physically unattractive (eg ugly/short), have serious health problems/disabilities that affects their ability to find a relationship, have serious confidence or mental health problems, have standards that are too high etc etc.
Your actual post, true in some cases-many other reasons.
If someone has no friends either as well as no dates, that would make me think personality was more likely to be the problem. Whereas if someone had friends but couldn't get dates, I'd think it was probably their looks.