I don't think it's an overstatement to say that modern compression applications often hinder, rather than accentuate, the human side of both guitar playing and music in general today. Judas Priest's last album had at least a few killer tracks, but the entire thing was so over-compressed as to make it uncomfortable to listen to for more than a couple of songs at a time. One of the things that suffered most from it was the guitar leads, which on their own were often quite fine. The produced sound just squeezed the blood out of the whole thing; it's hard for a listener to find a way to immerse him or herself into something so crushed of dynamics. And the same goes for general heavy metal guitar processing in this era; for all we know, really good players like Chris Broderick and Jeff Loomis could be the most expressive players of this time, but I doubt we're made capable of fully appreciating the nuances of their styles given the way their parts are processed. Paucis verbis, the guitar tones of today too often sound boringly similar, despite there being tons of great players. I could be wrong about some or all of this, but that's what I hear.
I remember recently reading about how today's listeners are so used to everything being perfectly in tune and practically everything being perfectly in time that producers are urged to stay along that path as much as possible. I can't think of a quicker path to soulless robot-ville than approaching music this way.
The processing of today's female Pop vocals are the worse victims of this approach. Besides the Pop singers whom obviously do have talent, there are hundreds if not thousands of female and male singers in the genre who sound almost exactly alike.
I can't finish without mentioning there are many wonderful, state of the art effects out there, many of which do enhance the music. However, from an overall perspective I feel there needs to be another Punk/Grunge style revolution in Pop, Rock, and Metal today, especially in the oh so important producer's realm.
That said, It might already be too late for Rock and it subgenres now. It's last gasp (Nirvana) was basically Jim Morrison writing lyrics for a set of Black Sabbath worshippers. In fact, the last great Rock album might have been (wait for it) Appetite for Destruction. And will be until the balls grow back.