The RGB pixels are on strike.
Apple's one-button mouse was a design statement.
To get a context menu, you held the control key while clicking. As for scrolling, well, you drug the stinkin` scroll bar(s).
Of course, everyone knows mice should have at least three buttons, just as pixels have R, G, B, and A (alpha, or opacity).
Today's Apple mouse arguably has many more than three buttons, albeit virtual, not real. And the scroll bars appear when scrolling and disappear the rest of the time.
Purity of design has its limits.