That's tenured academics. A lot of academics are still struggling to make a name for themselves, which means more like: pick an interesting problem. If it gets

That's tenured academics. A lot of academics are still struggling to make a name for themselves, which means more like: pick an interesting problem. If it gets any attention whatsoever, work on it and its variations for years. Maybe drill down into increasingly niche subsets of that problem. If at some point it appears there is no solution, make one up and defend it anyway, or add unrealistic constraints that will never be generally applicable, then promote the hell out of whatever you've got.