The photos show why every magic mouse I've had always wore funny with the 'right button' getting mushy. There's only one microswitch and the right one is just a leaf spring.
Think about having one plane (the entire glass) pressing 2 microswitches. Debouncing one switch is hard enough, now you've got to debounce 2, and detect if the user was doing a really fast double click, or just pressed in the center of the mouse.
Debouncing buttons is a solved problem at all. Thinking that Apple is so good that they put the charging port out of a reason to the bottom but aren't able to debouce two buttons is silly.
