Good for the goose, good for the gander.
As for why we shouldn't be able to, there are two good reasons:
1. If everything is priced at a regular price, no one in "underprivileged" markets will be able to afford those games, so cue piracy.
2. If everything is priced at the price point of "underprivileged" markets, it makes zero sense to produce those games, as it would mean that the company will surely go broke by doing so.
If not directly, they still benefit indirectly from any downward pressure put on wages.
Piracy is inevitable. No matter how low of a price you set for it, there will be countless people who'd rather have it for "free".
It's actually fairly difficult to just buy labor from another region without doing the equivalent of "buying a regional console" (i.e. building a local office/factory, where people actually speak the right language).