There are a lot of people posting here. In most of threads related to sportsbetting, most user just discuss about the match, how player performed, how they could perform etc but very few person discuss about odds, chances of winning a team and other factors related to bet.
You can even find many posts about prediction in ANN thread of a Casino/SportsBook. Yeah 90% are discussing about the match, player, score, statistic etc without discussing about what is called by gambling but I think it is common thing as long as the post is not out of the topic.
That discussion is already part of the gambling discussion, why I say that? because if we gamble we look at the stats and analyze before putting a bet, anyone that shares his bet or pick without stating the stats as a basis is gambling blindly.
Is it possible that most people only discuss here to fulfill their signature requirement?
Do you really need to ask about it? I believe it is a well known secret already since few years back.
No, his question is "only discuss here" just to fulfill the requirement, I believe it's not true as there are still some who joined the discussion even not wearing a signature on their profile.