can't be compared to old school rock but to look at it ironically, it's the old ones are more known and missed compared to the new ones but those new ones will be old as well....a cycle.
Metal has kinda been tarnished by being mixed with other genres, alternative for example. Music is always evolving, because people don't want to listen to the same stuff all the time, I still enjoy many of the nu metal bands today. Sure its not as epic and original as the 80s, but its still good. The thing I really agree with you on is how metal suddenly seems to have a formula for success. Rap and Hip-hop have similar formulas, but I didn't really notice it in metal until I started playing guitar hero games. I like the old, but I like the new too. I love all music.