Tenancy has strong and unique protections. If you are a tenant you can call the police to kick out your landlord if they are not within their access rights. Someone has the exclusive right to use the space, but it is not the landlord.

I think both of us have a very strong sense of property rights, only we disagree who to ascribe them to. I think it belongs to the airline, so if the man wants to create a dispute with the airline, he should be the one to take it to court (and he probably will.) From my POV, you are saying the man has property rights over the seat because he had a ticket for it and had his arse is in it.