Originally Posted by Reckless Eric

It is not a genre of music.
It is a term that groups together bands and artists from Germany who started around the late 60s and early 70s. But certainly not a genre.
Kraftwerk don't sound like Faust. Can don't sound like Cluster.

As for the bands not liking it, it's insulting. Imagine how French musicians would feel about the term Frog Rock.
Although, admittedly, it does sound kind of cool, now that I mention it!!