CEO says "I want to make more money". Crowd responded "No shit".
I've seen a theory that Steam is holding, possibly even for a time when Sony puts it in writing that players won't need a PSN account permanently before they're willing to relist the game which I think is a fair desire at this point.
It’s like an administrator/tenant relationship. Generally, the publisher controls the region locks, but if the publisher starts doing something potentially illegal or brand-damaging, like selling a bricked game, the store owner can also manipulate the locks.
If they couldn’t, a dev’s efforts to willingly commit brand suicide by releasing a game that bricks people’s computers (not beyond the pale given how stupid publishers are now) would also take Steam down with them.
That makes sense, but I haven't seen any official announcement from Steam saying that they did this. Only speculation from random people. Any documentation I can find just seems to point to this being a decision that's made by the company releasing the game (or in this case Sony as the publisher).
I doubt that Steam is still trying to block additional countries given that Sony has already announced that the PSN account requirement is being withdrawn.