mshilarious said:
We still haven't blamed anybody for squishing. I am hesistant to name NIN or Pumpkins or bands like that, because that was probably an intentional artistic choice, and somewhat suited to the genre.
The first big album I heard inappropriately squished to death and wonder why they wanted to totally destroy their record was RHCP's "Californication".
It would be interesting to find some information from "insider" producers and engineers regarding this. I'm not sure - one way or the other - that a "smoking gun" album could be properly identified. My impression has been that this trend has it's roots as an evolution of pre-existing trends infused with some marketing hype, more than as a seminal artistic pivot point.
On the marketing side, it has a geneology that dates back to AM radio advertising, but that's more like a grandfather than a birth mother of the phenomenon.
On the music production side, similar things with volume and RMS were done at places like Casablanca Records during the unfortunate disco craze of the 70s. After that it could also be found in much of the synth-heavy releases of the 80s where it was easy to boost RMS because there wasn't much dynamic range to begin with.
There are additional influences from the movie soundtrack industry, which in the 80s and 90s was a very dynamic (pun intended) force in the area of pushing music RMS on their soundtrack releases (again, more for marketing and effect than for fidelity.)
Then there was both the competition and merger with the explosive popularity in the early 90s of the various genres of rap, which by their nature also have very thin dynamics and in-your-face production.
So, as to whether there's an alt/rock/grunge album that could be called a "smoking gun" or "vanguard" that sparked the modern volume wars, or whether it's more of an evolution where several poped up sopntaeously, I'm not sure. It would be interesting to check out, though.

In the meantime I'd agree that RHCP were probably among the first of the new breed to push it purposefully.
G.