Why art is more forgiving than game design

The full interview is here. This is the relevant part:

I’ve also been working with a friend on a multiplayer game called Buy That Guy that you play with a map and cards. Each player represents an interest group such as agribusiness or tech, and you buy and sell legislators who you can use to pass bills that get you money. The goal is to become the political leader by controlling the majority of the legislature. It’s cute and almost playable, but the game mechanics don’t quite click yet, so we’re still trying to figure some things out. I think that art is a little more forgiving than game design. If you have a play that’s 90% there, people can enjoy it, but a game that’s 90% complete isn’t going to be fun enough to play more than once. We still haven’t quite made it fun, but we enjoy the process of working on it.