I'd like to complain about your post . . . j/k . . .
I think its the age old marketing saying that says something like, those that like a service tell two of their friends, and those that have a complaint tell 80 people they don't even know. Its just the nature of people's psychology.
That being said, I think FlyerTalk is full of compliments. Many regulars to trip reports very frequently--the thing to remember is regulars also will point out nuances that they encounter, so a thread that has a ton of positives might have a negative or two within it. I certainly have done this a few times and I find that most of the responses focus on the one negative, versus the three or four positives. I also think FlyerTalk has a lot of people that genuinly want to help the airline--since they seem to spend more time on a plane than with their families. So, they compliment in their trip reports but they also criticise where they see fit. Afterall, we know that most airlines have someone monitoring, if not participating in these threads as its a free focus group.
Given the state of the airlines and the morale that a lot of their employees face, I think its important that we do give compliments (some people can be motivated very quickly through them, even if there's no $$$ involved) but that we also still point out where things go wrong. Unfortunately, there's just a disproportionate number of people that post about the latter.