In the past, I would have focused on the adventure, the excitement and the interactivity of it all. Today I would still do that, but I would also focus on the things that mean more to me these days; playing with family and friends.
I'd also point out how it is a great creative effort. Want to write an 11 backstory for your character? Sure! Go ahead. But keep in mind they might die at any point. What to do then? New character and new backstory!
There are so many reasons people get into RPGs now and so many different kinds to choose from. Getting people into RPGs may not be the right question. Instead, how do we help people find the right RPG for their needs and wants?