Motive was always a question with these murders, maybe someone in that group called him a fag (seeing that pic) and he went on a ballistic murderous binge.
More like wanting a girlfriend above his level is the prime cause. Young men don’t realize they have the most freedom to create the best life for themselves and not tied down to the responsibility of a family is really a blessing towards that.
Sounds very plausible. I suspect he was fixated on one of the victims, likely stalking prior to the murderous rampage.