Imaro
Legend
Heh, I've only ever run into one individual who refused to play anything other than D&D. Conversely, I've seen a lot of wide eyes when I introduce people who've never seen a non-D&D to another game system, and how differently it can treat activities (especially Vampire. If you ever want to break a minmaxer, introduce them to a politics-heavy Vampire game).
Dominate... max it out...

EDIT: To address another aspect of this post... I've introduced plenty of my friends and family that started playing with D&D to other systems... we've had fun and even gone back to a few but our staple and most requested game stays consistently 5e since it was released. Anecdotally and all that of course.