Much like the changes to the draft I think people will complain about it, but at the end of the day it has little influence on fans and if it does fans will just adjust accordingly.
It hurts the boarderline players in that they won't have as much game time to prove their worth, but I'm sure the players union will demand that rosters be expanded. I'm not sure how much 4 games really prepares the players as it is, as most teams don't (or rarely) even play their starters in the 1st and 4th game anyways. In 4 preseason games most starters only play a total 2-4 total quarters, and in a 2 game preseason they may play 2-3 quarters.
These guys are professionals, so they should be ready. There was a time when training camp was simply about getting guys in shape for the seaosn; however, guys these days are expected to come already in shape. Teams changed the purpose of OTAs and training camp from being mainly about getting in shape to learning the offense, getting timing down, etc.