This is part of why HP was so special. It grew fondness not just for those who were children at the time - but all ages.
Trust me, I'm one of the biggest gamer and Nintendo nerds you will find. I have so much gaming history and $$$ within arms reach of me right now. But know what? My wife doesn't care.... my parent's don't care... only about half my kids care. And this goes on and on and on across so many families.
Mario is HUGE - but Mario as a passion is still tied to certain demographics. HP is broader.
Heck, I'm wearing a National Video Game Museum shirt right now for crying out loud