Citation needed. “As little OS as possible” would mean not having a standard clipboard, not having a standard way to install fonts, etc.
Even interpreting that as “all the functionality, but limit applications to utilities for managing the hardware”, I think there people who want that, but I doubt that’s what people, in general, want. Having to choose (and, likely, pay for) a photo manager, a simple word processor, etc. is just too much of a hassle for many.
Also, why would any commercial entity develop such an OS? The margin is in the