I am going to teach my kid to rebuild a carburetor and how to change the needle on a 45 rpm record player so that when they drive a modern car or use an mp3 player, they will have the skills needed just in case.
Times have changed, kids have changed. What worked for you and us 20-50 years ago may no longer apply guys. If they learn on a 15-22, that is what they will use. All of the same safety and discipline skills still apply, you just have to change YOUR thinking and get with the times. If you force them to do something they don't want to do, they may give up. You used a bolt action .22 because that was what was available then. If they had 15-22 30 years ago, your dad would have been teaching you with that.
All that being said, I like the 15-22 for the cool factor and it is a blast, but I also like the 10/22 as well. Yes, the 10/22 will probably last longer as my dad has one that is as old as I am, but who's to say that with proper care, the 15-22 won't be the same. If you like modern and tactical look, with a real ease of maintenance, go with the 15-22, if you want rock solid old school, proven reputation and like the style, go with the 10/22. Both are equally accurate for the casual shooter and equally deadly and dangerous.