I guess I'm in the minority that still worries about it. I won't bid on a book if I know it has been pressed, but most of the time I don't know. I do search HA for old scans, and if I see that a book has been upgraded, I won't bid. Most of my books won't be pressed in my lifetime because I don't intend to press them or sell them. The few books that I sell will probably be pressed by somebody else.
If pressing isn't going to be considered restoration, at the very least it should be considered damage. A flattened crease that is still detectable should be penalized more heavily than a crease that hasn't been flattened.
I also hypothesize that the humidity that books are exposed to during pressing initiates rusting of the staples. I see far, far more books with rusty staples than I did even 15 years ago, and the advent of the pressing craze seems to be the watershed.