I'd agree with that, except the word "grunge" itself is a BS marketing term. "Alternative Rock" is even worse (a mainstream alternative to the mainstream?)
"Indie Rock" is more descriptive but kind of boring (Thurston Moore once used the phrase "Indie Guitar Swing".)
"Post-Hardcore" has a certain ring to it (like the American version of the UK "Post-Punk" thing of the late 70's.)