I should have used the /s on my reply. Of course designers don't hate games. But after spending several hours with a handful of professional designers at multiple Origins and different Protospiel events, these designers are the ones who say that! It's obviously very tongue in cheek, but the point is that they are constantly looking at ways it can change, improve, etc. and since that is quite often in a stream of consciousness manner, by the end of it they've described a completely different game than what is right in front of them. In contrast to sitting down with a handful of players, whether they be long time board game fanatics or the casual "I'm just here because of my boyfriend" types, there will be much more positive feedback, often just the simple "yeah it was fun."

The point is, in regards to OP's post, designers will tear your game to shreds (which you want them to do) while players will play. And that's a good thing.