Academics do make and play games. But being novel doesn't mean they'll be fun or accessible for a general audience. And there's a lot of work that goes into a video game beyond just thinking one up: game engines, making art assets, packaging and distribution. That work isn't necessarily going to appeal to the same people.
Just look at Miegakure for an example of how long it can take to go from an idea to a fun, polished game.
Just look at Miegakure for an example of how long it can take to go from an idea to a fun, polished game.