Some observations.
-With the exception of Slaughter, all of the bands featured still tour and/or record regularly. This helps.
-Bon Jovi isn't on here, but then again neither are Def Leppard, Whitesnake or Guns N' Roses, all of whom could be included on at least a borderline basis. Def Leppard and Whitesnake sold A LOT of fu**ing records, more than most of the bands on the list. Great White was reasonably successful, though it is pretty clear why they are not on the list.
-If Bret Michaels wasn't all over the radar again with his television shows and appearances, I'm "pretty sure" Poison would have been #2 and Motley Crue would have finished first. Pretty sure.
-Shotgun Messiah recorded some pretty good music, but nobody would ever think to include them because none of their albums were widely successful, their sound changed each time out and they went through two singers over the course of three albums. However, it wouldn't have been a huge stretch to include them just to mention that bassist and singer Tim Skold ended up in KMFDM and Marilyn Manson.