Interesting, I guess I haven't played anyone over 2000 with it but I can consistently beat the local 1900's that rely on it.
Actually a player locally here, named Jeff Johnson (or maybe Johnston) is the one who told me to always attack the junk side. He's won the hardbat US Open a couple times, so I trusted his advice. But then again it could probably just be advice he was giving me just for the level that I'm at.
OK, since what I said and what he said are both half-truths, let me write a bit more on it.
There are players who went to junk rubbers (I am not a fan of the phrase) because they realized that it suited their game in one of a few ways:
1. Their coach trained them to use it, or it just fits their personality and they got really good at using it - I know people whose pip game is their strength and their inverted game is not even a factor. They chop block, hit and dead block impressively even with medium or long pips, and their pip attacks are even stronger than their inverted attacks.
2. It enabled them to stay closer to the table and take the ball off the bounce - this is a common reason for using pips and anti of all kinds, and it is combined with my next point, but let me leave it as a standard point.
3. It enabled them to set up their forehand loop vs. underspin. Players like Danny Seemiller and John Wetzler in the US use anti and long pips on the backhand for this reason.
4. It enable them to chop better - see defenders and modern defenders.
5. They struggle to read and control heavy spin generally and need something to switch the tempo up.
6. They realized that their backhand or forehand inverted game (or both) would never be topspin away from the table, sometimes for health reasons, so they wanted to change to something that might give them an off tempo advantage.
Most of the people you are talking about are in category 5 and sometimes in category 6. But even some people in category 5 and 6 sometimes end up being in categories 1, 2, 3 and 4 over time.
This doesn't change the broad principle you pointed out at times, and I think when you play against pips, the truth is that you tend to end up learning to play against the pips rather than the player because they are relatively limited in their rally spin generation if medium or long so that experience lets you treat players similarly. But if a player learns to attack with his pips, that often changes things. And if a player has a good inverted side and becomes very skilled at setting it up with the pips, then you have a pretty high level player. In a sense, the pips side is still their weakness, but it has a purpose that you cannot underestimate especially if you don't practice enough against the kinds of balls you will get from the pips.
USually, I divide pips players into two, those who only dead block and those who dead block, chop block, and hit/attack. The former tend to be under 2000, the latter tend to be over 2000. There are exceptions here and there, but that is the general rule.
To give an example: If my inverted backhand wasn't so strong relative to the rest of my game, I would have been a prime candidate for pips because I like to attack backspin. I would probably learn to do many things with them.