Yeah its really annoying, since so many people say something would be a different subgenre or genre that are similar you never even know if you are right.
Like if someone said ELP was techno. And another person says they're electronic, and another would say they're progressive. But I'd just say they're Rock and get on with my life.
Back 40 years ago, you would say something is Blues, Rock, Heavy Metal, or Classical and there really wouldn't be much arguing cause each sound was clear cut. But now styles are seperated by one or two different elements. Such as Pop-Punk and Punk, the only real difference is the vocal style.