So Snoke apparently has some Osteoporosis-type situation according to Andy Serkis, and his deformities drive his intense hatred.
They easily could have played off that he was never appreciated by Jedi, or maybe even the Sith, and wanted to show that he had just as much as power to rule - and when the Empire fell... he found his entrance. He realized he needed an apprentice and started hearing about the grandson of the great Vader and started to lure Ben over. Easy connection to give to at least care a bit.
Furthermore, this guy didn't just lure Kylo with him - but the Knights of Ren are all Luke's former students so..... he's got some swag...
ALSO WTF - waste of KoR too.