The average adult gravitates to games for the theme or nostalgia (which is why modern Sterns, older licensed games and Bally/Williams do the best on route, with everything else trailing behind in a distant second). I saw someone saying that Bally/Williams are popular because they're simple, but if that were the case then the early SS and EMs would be as popular if not more. Expecting kids to magically have the same level of interest in pinball as the collectors is unreasonable, as others have said playing pinball with them will help to foster a interest in them to maybe explore it more on their own as they get older.
I have been told multiple times by family who come over that they don't want to touch my game collection because they're scared they'll break something. I have to convince them to turn the games on, they're meant to be enjoyed dammit