It stems from a bias, developers are power/expert users and their interface behavior is likely matching, which means they are heavily reliant on keyboard shortcuts (Think Blender 1.x and Blender 2.x who leaned heavily and even exclusively on shortcuts)

This gives them the idea that their software is very powerful (and probably is) but this creates a cliff to the beginner and intermediate level users.

A lot of examples can be found in “About Face: On interaction design” by Alan Cooper.