Someone has said it on this site before, I think it was Brogan, but the problem isn't that Tilke is necessarily a bad designer but the only one that is used to design tracks and therefore they all seem to be the same. This problem is further compounded when his hands are tied by Bernie - "you must have so and so corners and so many straights". So a creative man is not even allowed to be creative - a sad indication of the times 

OK, so it doesn't prove anything, but it does show that they're not all bad. And this is the designer of the wonderful turn 8 at Istanbul, as well as challenging fast corners at most of his circuits, and a decent Chinese circuit despite being told it had to look like a character from the Chinese alphabet.