That's probably a bad design on the part of the microwave maker. We still use tons of 3d buttons everywhere, and everybody is familiar with them.
>On a computer the most common button-like thing is a web link and those don't (generally) use the 3D-effect.
Links are links, not buttons.
I suspect that most people would have trouble coming up with a definition for a UI button that couldn't just as easily describe web links.
Buttons perform actions (that might also present a new panel).
The problem is bad UIs muddling the waters between the two (having a plain text "label" looking like a link that does "Delete everything in my account" for example).