The "exploiting" part doesn't come from the ability for children to make money. It comes from the company taking 75% of profits and having a pretty massive minimum bar (100,000 Robux / $1,000 USD) which must be passed before the person gets to withdraw anything at all, which is then effectively double taxed because the company will then only give $350 for 100,000 Robux when cashing out to actual money.
It's all designed to get a huge amount of free labor, while hiding how outside of a lucky few who benefit from the network effect, the average would-be game maker ("slum kid" or not) would be financially better off just using a standalone toolkit to make their own app and selling it on Itch or Gumroad.
It's all designed to get a huge amount of free labor, while hiding how outside of a lucky few who benefit from the network effect, the average would-be game maker ("slum kid" or not) would be financially better off just using a standalone toolkit to make their own app and selling it on Itch or Gumroad.