This thread was in response to a quote from another thread that spoke of people responding as if 4E should be immune to criticism, and my response that a lot of the so called criticisms are statements of preference as opposed to discussion points, and other ways that "criticism" isn't criticism. After recent posts, I would add that a lot of negative 4E comments aren't criticism as much as they are salvos in an "edition war".
I'd say that it's definitely not "constructive" criticism. There are definitely things that can be fixed that need to be addressed, and some confusions that popped up. Heck, lots of people complained about the skill challenges and it got errata'd. Some of those problems seems to be tied to problems that pop up a lot in any kind of game ... especially when the people designing and the people playtesting are on the same wavelength ... they know what a power is supposed to do, but they may not necessarily know how to word it, so you end up with RAI vs. RAW issues ... or in the case of the skill challenges, there seemed to be some sort of expectations (I think I remember in one of the pre-errata defenses, the intention was a lot of use of aid another being assumed to make it possible).
Anyway, there is a big difference between pointing out problems in the system, especially ones that can potentially be solved (even some of the "the system lacks X" can translate into "they should have this class in the next edition") and just nitpicking.
4e isn't immune to criticism, heck, criticism helped bring about actual changes in the game, most notably the skill challenges, but some other things like the errata of the ranger power to "one-shot Orcus".
It's just that a lot of what passes for criticism is not only not constructive feedback, it's also a lot of "next verse, same as the verse", some of the same complaints/criticisms made at the game's released and most of the threads end up going over the same ground. So if they are immune to anything, it's to the arguments that have been tossed at it over and over again without much effect.