I agree with you. My SO's family chose to stay at an airbnb for our wedding this fall so they could have kitchen access. On one hand it comes down to convenience - it's easier to buy a couple boxes of cereal and a gallon of milk and some sandwich supplies rather than find a place to eat 3 times a day. I suppose a hotel could have a mini-fridge, but that wouldn't be able to hold enough for them. I've stayed in a suite with a full-size fridge, but that was considerably more expensive.

There are 5 of them, so that's a factor too. It's easier to plan/use up groceries for multiple people over multiple days than if you're just alone.