I don't get it either. I'm sure this was covered in another thread but since you brought it up.
Having read through a few upcoming Auction catalogues, I fail to understand how a poor quality note that is nearly unrecognizable in some cases gets to be labelled PPQ or EPQ. Really this does not make sense. Did the grader go back in time and base it on what the paper quality may have been then? How can you possibly judge the paper quality like that. Is it premium because it managed to stay in one piece? These days it seems to be all about embellishment and tacking on useless adjectives to help sales. The same thing happens with coins.
Best advice is to 'Buy the coin or Banknote, not the holder.' Learn to grade conservatively so you can avoid paying too much for overgraded items and take advantage of undergraded stuff that you can hopefully make a few bucks on. I'm sick of seeing 'Mint State' coins with scratches, significant wear on high points and even labelled 'cleaned', that clearly do not belong in with the better preserved items. Even Banknotes that are laundered and trimmed seem to be accepted.