IMHO there's a difference between two parties negotiating from a clean slate, adding and removing things back and forth, and someone sending out a "take or leave it" contract form with clearly no intention on modifying the terms.
Rarely do two parties negotiate from a clean slate, in fact the beginning of most contract negotiations I've seen is who's slate should we start with, mine or yours.
Sure, but the EULA is starting from one slate and then nevvvver moving.