No reason at all to do that, you can give the kids a great machine that they can use for the internet and games, but strictly limit when it is connected.

I don't know if modern laptops can do this (modern ultra-portables can't because everything is soldered in), but I recently took the wifi card out of my (ancient) T61, it required only taking out screws[0] and disconnecting the daughter board, so that I would have a machine without always-on-internet. Haven't had much use of it, but sitting in front of it, I have caught myself starting up chrome...

[0] sadly I failed to keep track of which goes where, but that is also the only issue.