Opinions on why some don't like prog metal?

This is about how I feel. There is also something about some of the singers too. Some, not all, remind me of 80's hair band vocalists and I never liked that style of singing. 

You are indeed on target, I could not say it better.

One thing I could add is the fact that the 80s influence is quite predominant, forgetting about the legacy of the 70s hard rock or metal bands, like Black Sabbath, Uriah Heep, Deep Purple, etc. Their sound was original and distinct, not like the metal of today. I find it very hard to see a difference of style on today's bands, and most guitarist have the same sound (The Eddie Van Halen sound to be more specific). You could very easily tell Ritchie Blackmore from Tommy Iomi, or Jimmy Page for example, which is not really the case today. 

It's interesting because I remember hearing Alan Holdsworth with Gong and noticed the same distortion levels and sustain of Van Halen. Of course Van Halen was deeply influenced by Holdsworth. The riffs, the technique, and the sound. To get that sound one would have to surely apply a full-lock sustaining sound. If you listen to Holdsworth's soloing on Soft Machine Bundles, you may pick it up.....again, you may not. When Holdsworth plays power chords with Gong, use an EQ or try to imagine the chords without the other instruments and it sounds like metal. Actually heavier than Steve Hillage. (Live Herald). and a bit more like Van Halen.

 

Van Halen was also infuenced by Jeff Beck. I'm going the distance for him and I hate his music. He can actually play decent but is thought of in the vain of a cartoon character. The reference you make which is based on the difference in players from the 70's is telling. Not just their sound was different but, their approach in what is defined as practices. They were diverse players but their methods of development were quite different from 80's guitarists. I felt putrid over the "Buzz Saw" sound. Tom Schlotz, Lonesome Dave Peverett, Randy Bachman, Mark Farner, and Leslie West. It's too easy to get away with cheating in the usage of this sound. Luther Grosvenor from Spooky Tooth had the Toni Iommi sound on "The Last Puff". His distortion level was comparable to the nightmares listed above however he had that British Blues Boom sound and it was very complimenting to the music.  When you hear Blackmore solo in "Lazy" from Machine Head, Rory Gallagher on "Live In Europe" and Clapton on "Crossroads" you wonder why the sound had to change? Andy Powell or even Scott Gorham and Brian Robertson from Thin Lizzy had a more diverse approach to the usage of distortion.    

You are indeed on target, I could not say it better.

One thing I could add is the fact that the 80s influence is quite predominant, forgetting about the legacy of the 70s hard rock or metal bands, like Black Sabbath, Uriah Heep, Deep Purple, etc. Their sound was original and distinct, not like the metal of today. I find it very hard to see a difference of style on today's bands, and most guitarist have the same sound (The Eddie Van Halen sound to be more specific). You could very easily tell Ritchie Blackmore from Tommy Iomi, or Jimmy Page for example, which is not really the case today. 

It's interesting because I remember hearing Alan Holdsworth with Gong and noticed the same distortion levels and sustain of Van Halen. Of course Van Halen was deeply influenced by Holdsworth. The riffs, the technique, and the sound. To get that sound one would have to surely apply a full-lock sustaining sound. If you listen to Holdsworth's soloing on Soft Machine Bundles, you may pick it up.....again, you may not. When Holdsworth plays power chords with Gong, use an EQ or try to imagine the chords without the other instruments and it sounds like metal. Actually heavier than Steve Hillage. (Live Herald). and a bit more like Van Halen.

 

Van Halen was also infuenced by Jeff Beck. I'm going the distance for him and I hate his music. He can actually play decent but is thought of in the vain of a cartoon character. The reference you make which is based on the difference in players from the 70's is telling. Not just their sound was different but, their approach in what is defined as practices. They were diverse players but their methods of development were quite different from 80's guitarists. I felt putrid over the "Buzz Saw" sound. Tom Schlotz, Lonesome Dave Peverett, Randy Bachman, Mark Farner, and Leslie West. It's too easy to get away with cheating in the usage of this sound. Luther Grosvenor from Spooky Tooth had the Toni Iommi sound on "The Last Puff". His distortion level was comparable to the nightmares listed above however he had that British Blues Boom sound and it was very complimenting to the music.  When you hear Blackmore solo in "Lazy" from Machine Head, Rory Gallagher on "Live In Europe" and Clapton on "Crossroads" you wonder why the sound had to change? Andy Powell or even Scott Gorham and Brian Robertson from Thin Lizzy had a more diverse approach to the usage of distortion.    

Once I read an article on this subject, I think it was on progsheet.com. I just looked for it but could not find it, but stressed the evident difference between guitarists before and after Van Halen. As you mentioned, not just their sound, but their approach was quite different.

I think also the state of the music industry was different and quite influential, since the 60s and 70s were more of a "Be yourself" an allowed bands to be more unique and expressive, whereas in the 80s and 90s music in general was more mainstream, meaning you had to fit into the sound/trend dictated by the industry (You can find references to this in the film "Before the Music Dies"), and it has limited many artists in their output of creative music, not only in rock, but in every genre of music. 

That being said, I also find many bands in any other prog sub-genre to be bland and predictable... It's just a matter of what hits you musically and what doesn't.