Does that surprise you? It shouldn't. Try coming up with a glib definition of "Rock music" that manages to capture the unique qualities of AC/DC and Ash Ra Temple, and all points in between. Good luck.
Sure, people have tried. You do get people making ill-advised attempts to provide definitions that involve waffling on about Blues-derived stuctures and chord progressions, but does that mean you can listen to a John Lee Hooker track and thus get a fair expectation of what Can's "Father cannot yell" is going to sound like? Short of an extraordinarily lucky prophesy brought on by weapons-grade hallucinogens, I doubt it.
The same goes for Jazz too. Explain the sound of Duke Ellington in such a way that also covers the sound of Ornette Coleman, if you ever feel like a spot of masochism. That's the trouble with umbrella terms in music, but it's only a problem for the sort of Aspergersy types who feel a desperate need to have neat, one-line definitions that cover huge swathes of popular music. If you're one of those people, why not try getting a hobby instead? Masturbation is a good one.
That doesn't mean we don't have standards here, of course. If you want to talk old-school Industrial (Throbbing Gristle, SPK etc) we love you and want your babies. If you want to talk EBM, Coldwave etc, we'll babysit your kids for you. Noise, Power Noise, Power Electronics and all those other electronic monsters that make your Dad shout at you? They're all good. Modern Industrial with all that distorted vocals and "OONTZ!" stuff? That'll do. Industrial offshoots like Neo-folk, or cross-pollinating stuff like Synthpop? All good. Weird electronica like Autechre, or odd Musique Concrete like White Noise? Yep. Hell, we even had an Emilie Autumn thread once, and I didn't even hit anybody. I did bitch, though. Boy, did I bitch.
So it's quite a wide banner, really. If you're confused, just ask if it fits here- go to the staff, or ask in the social thread.