With parents as busy as Leia & Hans its easy to see why the son got interested in the dark side. It is powerful while the parents were weak.
He may have gone “dark” because he hated a good side that said he had to be abstinent while being a healthy and powerful young man.
The irony being aside from his grandfather, the Jedi and Sith were both overwhelmingly not breeding. Then again, that could be a reason to worship his grandfather - Force powerful AND girlfriend.