No argument there, Olias, as long as it's something truly constructive, and not simply yet another fanboy- (or girl-) type acknowledgment like "that looks great!" The whole point of the forums is supposed to be as an information exchange. Once a thread has been dormant for months, anyone resurrecting a thread to merely comment, without providing any NEW information, is not really providing benefit to the community as a whole.
I have seen in the past several NEW members dredge up long-dead threads simply to say "I like it," which is great, but adds no value to the original poster, or to the community as a whole. Now, if they have a question about how somehing was done, or use it as a point of reference, such as "I want to know how to do this...," then by all means, dredge away...