Re "I have better things to do..." - No you don't.
Funny how some people seem to think that physical competition (such as cycling) is somehow "grown up", yet more sedentary competition (such as computer and other games) isn't. Unless the game is, say, chess or bridge, when it suddenly becomes magically grown up and acceptable again...
I also started playing computer games in the 70's (along with board and role-play - all social activities, in case you hadn't noticed, and just as valid IMO as, say, hoofing a soccer ball around a pitch once or twice a week). The difference is that I never stopped (in fact, I've a Warcraft session running full screen on the other, 24" monitor of my PC as I type - and let's see someone do *that* with a tablet any time soon....). It didn't stop me playing multiple sports, coaching rugby, learning to juggle, having a career and a social life, being happily married and raising four kids, and generally getting on with a host of other, unrelated things along the way. You wrote a book? Bully for you. That you did so had precious little to do with your not playing games. I've found time to write plenty along the way myself (although I realized quite quickly that I'm far too florid in my style to be commercial, and far too anal about consistency of detail to ever finish anything to my own satisfaction anyway). But I didn't "not grow up" - I just never learned to be embarrassed about doing things I enjoy, simply because people whose opinions I couldn't care less about don't understand them. I try things that take my fancy, and I don't give a toss what other people think about them (I've been trying to learn some basic Poi for the last few weeks - finally got the hang of a simple move called the three-beat weave about four hours ago, to my intense elation). My advice to anyone who feels differently is to lighten up, and enjoy life while you still have it - you'll be as dead as me in a couple of hundred years (and unless you're another Shakespeare, just as forgotten, too).
Back on topic, though - IBM didn't understand what they had when they brought the PC to market, or they'd never have let Microsoft have the OS - and they were thoroughly focused on the tech, back then. Why anyone should think any of them know any better now, when all that counts is squeezing a few extra bucks out of the bottom line any way that they can, is beyond me. Other people have said it - the PC hashigh-end roles that simply aren't going to be met any time soon by the supposedly "competing" tech.
(Oh - that career I mentioned? Pushing four decades as a techie inside IBM...)