I agree with Kopper...I hate this shit. But I also agree with Gringo Starr and the criteria he wrote that defines "rock and roll" (very diplomatic Gringo) and if some "hard rock" fits into that criteria for some of you, then listen to it.
When I was in high school back in the day (I'm Old!), all of my "friends" were into Deep Purple, Sabbath and Grand Funk. I hated that shit and thought it was stupid and pandered to stupid people who needed to be pandered to. Creem made fun of 'em! Now I kinda like those bands, mainly because they're stupid. Go figure!
In the 80s and 90s when a lot of these bands mentioned were at their peak of poularity, I used to love to watch MTV with the sound off. When a video for a "hard rock" or hair-metal band would play without any sound, all that was left was their ridiculous macho visuals and cum faces and rock-god poses. In other words, all that was left was all the reasons these bands and this kind of music sucks and will always suck. Corporate Rockstar dreams for 12 year old boys to buy at the local mall. "Edgy" and "dangerous", yet safe enough to be sold at Wal-Mart. Nice!
Everybody has some skeletons in their musical closets. Lets' trot them all out and make fun of one another because we have different tastes than the thing that brought us all here. Man, that sounds like FUN and a great way to be "punky". Or "hard rock-y".
Ultimately, unless you're being nostalgic for your younger days, why listen to this shit when there is so much GREAT stuff to listen instead of it?