"haterobics, these statements are not one in the same. So if I were cast as Susan instead of Karen, it would be totally ok with you, because I was doing my best? Has professional NY theatre now sunk to the level of "everyone gets a trophy for participating"?"
This is hard to answer, since your analogy about things not being equal is... also pretty unequal as I had no problems with Lin in the role and actually bought my ticket because he was in the role and in a show I enjoy. If I had a problem with what I saw him do onstage, I would have mentioned it, though. I just didn't have those problems.
"Just kinda feels like people think it's wrong to say it. Maybe it really is just a matter of taste."
Well, you're only experiencing the thread from one angle. The people who liked it keep being told how awful it was and what's wrong with us that can't even discern good singing.