While I agree that it is good to not always dwell on the negative, there can be a lot of value in pointing out the deficiencies of programming languages.

Some folks will just use a language without thinking about its downsides. If you use language X for a long period of time, you can become blind to areas where it is wasting your time.

Again, I do agree that the tone could often be much more civil, but I would hate for experienced programmers to stop pointing out things that bother them about their programming languages. Much of the time it is not just about personal taste -- it is about real problems with the language that have a real cost.