This is an excellent question. Its hard to make sense out of this apparent contradiction unless one examines the underlying premise of liberal thought:
1. no culture is better than another.
2. to think otherwise would be discrimination/prejudice/bias
ergo:
a. any culture that is prosperous (America, Israel) must have cheated somehow
b. any culture that is lagging (every muslim country) must have been victimized somehow.
Search “Evan Sayet” in youtube for an extremely insightful breakdown of this idea.
All the contradictions about liberals make sense once you understand this.