Charging for two seats together is just a blatant way to make money - inexcusuable. They still have to fill every seat, so are they going to go out of their way to make sure couples are not sitting together if they don't pay? That is just extra work for them.
Even if you go the cheapest route for the supplier where seats are assigned on a first-come first serve basis, since most couples book in tandem logically most of them would end up together or at least close.
I understand charging to change a seat (tho I may not agree, I understand) - which they are already do if you buy a "premium" seat. But otherwise it is just blatant money-grubbing.
Is there a word for "money grubbing?"