Upon further reflection, I think I've figured out why my kids and I don't see this as exploitative - they're not trying to get rich or famous.

I'm not trying to be mean to anyone, but if you look at all of the complaints through the filter of someone who wants to a) learn to make a video game, b) learn some programming, and c) make a cool game to share with his friends, then Roblox is a really fun, free, and easy way to do all of the above.

If your filter is a kid who a) wants to make a game that goes viral and earn a bunch of money off of it, then yeah - some of these are legit complaints.