Do Film Makers Want 4k?
In my opinion, the market for 4k delivery is still very small, but that doesn't mean its useless.

Shooting at a higher resolution than the delivery resolution allows you to recompose shots without any quality loss. If you shoot a talking head in 4k but deliver in 720p, you can get a wide, medium, and closeup from the same shot. 

In my experience clients nearly always want video delivered in 24/25/30fps. Higher frame rates should only be used to achieve slow mo. That being said, everyone loves slow-mo, so the ability to be able to shoot at 60fps or higher is valuable.