I completely agree the UI is pretty bad. The hidden side of it though is that anything you want to do regularly has excellent keyboard support. I don't even use the UI in blender most of the time and there's little to no friction, it's tremendously efficient. Problem is, new users have to get past the bad UI to get to that point and many never do. It's much faster to get up and running in Maya, but once you are proficient in Maya, you'll still be doing nearly everything by clicking buttons with the mouse. To me, that's the key difference.