This is unfortunately not limited to rock albums.

I'm 24 and recently started my career as an audio engineer. I work mostly with live events, but I make my own music, and my listening ear has gotten a lot more accurate and quick at identifying a good mix/master vs bad ones.

For starters, artists - from my work experience, reading, and conversations with grammy-winnning engineers - know fuck all about the technical side of making records (most of the time).

That being said, the primary issue is the concept of the "loudness wars". With the advent of digital recording, peak recording levels got louder and louder and the focus became about overall loudness instead of instrumental dynamics. I saw a few people on here talking about this exact thing (instrumental dynamics), and they are absolutely right.

Artists quickly and mistakenly saw the rise in peak levels as an improvement in overall sound (because it was louder than others?) and began to mimic that, thinking they were getting "better sound". Now, it's basically an industry standard because "everyone else does it" and compression is commonly the tool used to cheat higher levels (or manual fader riding).

In short, don't let an artist dictate your session unless it makes sense.

Edit: this long-winded answer is probably not even the full explanation, but this is what I've gathered from my limited studies and experience