I was thinking how ridiculous it seemed too. What I think might be interesting though, is if, in buying a row, you have a right to invite a third person, most likely, a member of your own household, to take the middle seat. Obviously the onus is on the travelling group to prove their affiliation, but if they do, that's a win for both the passengers, and the airline.
It's a better idea than what AA and the EU airlines are currently doing, at least.
edit - Obviously, I'm not advocating doing any of this in place of mandatory masks.