For me, I started about a year ago (I was over the age of 20 by then.) I started wargames because I couldn't find any new video games that had a level of customization that MechWarrior and Chromehounds had given me, that most games don't duplicate (and that most players of XBOX games seem to shy away from)
40K gave me that, and seemed to encourage it with an emphasis on conversions and customized
HQs and squads. Since then I've looked into other systems for more customization and more tactics.
At this point I could care less if someone thinks they are 'toys'

I'm only playing these games because they are the only games of their kind.