I think one of the reasons for it is that Jerzy's backhand is not good for both hitting and returning. Especialliy, when he face out-wide shot to his backhand.
It is his biggest weakness. So to defeat Jerzy, you have to place a lot of balls to his backhand wing. Accurated serve is Federer's trademark, so it does a lot of damages.
So it is area Jerzy has to improve in the future. He has good backhand slice and drop shot, but normal hitting and returning are not good enough. Single backhand can be his option.
I just hope Jerzy's coach knows this problem and has worked with Jerzy.