My son switches back and forth between Minecraft on his ipad and laptop regularly and with ease.

That's probably true, but I think most people don't have desktop computers anymore. Most people buy laptops instead, and they don't use a mouse. Hence, most kids growing up won't really interact with desktop computers and mice anymore, and won't really get to see how different the experience could be. Not unless they happen to be at a friend's house, and that friend has a desktop computer with a mouse.

Students in my class often don't have a laptop at home either, phones, consoles, tablets, but nothing to do any work on. All the open source software they're learning to use and nowhere to run it at home

Even a console-style controller would be a huge upgrade from a touchscreen and those are still very common.

You're making a lot of assumptions about touch controls. They work much better than you think for people who has grown up with mobile only.

I honestly can't see it. Sure the kids may be fast at swiping, but ... it takes milliseconds for a professional with a mouse to already have aimed and shot against the head of an enemy player.

There is a reason why pros who play with controllers never play against pros on PC in shooters. And I can easily imagine the controller pros will be much faster than swipers.

So, for just building with blocks, I can see why parents just give the kids an ipad so they don't have all the running and screaming, but it probably won't be a competitive way of playing games. I only say probably because I just can't imagine me watching someone swiping on a screen.

I'm not saying that it will be on par with PC or even console but check out this clip where you will see the touch in action to the left: https://www.youtube.com/watch?v=nf9r5S-tnu4

The main thing with a touchscreen is that it's probably not as long term solution for input for these fast paced games. The way you grip your phone is probably going to hurt your wrists more in the long run.