Regarding restoration, I used to say this right here about 15 years ago, and still, here we are, with Slight P purple labels selling at a dramatic discount to blue labels in the same grade as what the book was before the Slight P work was done. The education hasn't worked. I am pretty sure that serious collectors who spend on books like that know at least the basics of what restoration is, and the values still haven't closed the gap over time.
Regarding pressing, I completely disagree. Pressing doesn't exist because of some loophole, it exists because it removes or minimizes defects, and higher grade books sell for more than lower grade books.
Too many people chase labels whether they want to admit it or not, and would rather have a 9.8 that they know is pressed over a 9.4 that wasn't. There isn't going to be a magical Kumbaya moment where all of a sudden people en masse prefer books that haven't been pressed to the point where they'll pay the same or more than they (or someone else) will pay for the same book, pressed, and now grades 2 to 5 grade levels higher. As long as the pressed book sells for more than the unpressed book, things will remain as they have for the last 20 years. It's not a loophole; it's the nature of most collectors who chase high grade books.