Misogyny and loneliness
The problem is, our feminized society has given every woman the power to hold out for higher quality men than they deserve. This creates an imbalance that leads to tragedies like the one in PA.
A decent looking man who earns a good living and does not abuse women DESERVES to get laid. Period. The fact that so many do not, is a crime. And in a just society, all crimes are eventually punished.
Women at Risk
Misogyny at its Worst: George Sodini a "Hero"
Pennsylvania shooter targeted women
Women weren't to blame for George Sodini's spree
Gunman Murders Gym-Going Women; Misogynists Approve