They already said there will never be anything in game required to pursue content that would be available in the cash shop.

HOWEVER...

If the only way to share a house between two people is through the cash shop, that is an incorrect statement.

I feel like this person isn't pinpointing what it is exactly they are afraid of, and instead generalise.

I will be disappointed if marriage is only able to have two people share a house via a fancy mogstation purchase... but I will do it anyway. I want it, they have it, and unfortunately, where there is a market there will be buyers and sellers.