> What entitles any of us to use that domain?
You're right. I didn't pay for it, so I'm not entitled to get to use it.
Just because there is only one internet, and only one top level domain namespace, and just because I don't have $150,000, does not entitle me to get to use some part of the internet in the same way as a single corporation with a lot of money.
What entitles anyone to use the internet? I don't pay for the root name servers. I don't pay for peering transit. I don't pay for core routers.
I guess your point must be that corporations [and nations] should use their money and influence to acquire large chunks of the internet and screw with it in any way that they possibly can. And we should not care, because we are not entitled to it.