It’s called negative bias, which is generally a human trait.
I think when it comes to being positive about a team/player/manager it’s perhaps more a case of being concise and to the point (What a game Morrison had to today or Spencer, cracking player, and that covers it) whereas picking the bones out of being negative tends to be much more nuanced and prolonged, especially to the depths we went too, and length of time.
I reckon if we had a lengthy period of success, on and off the pitch, the number of posts on “The Falkirk Thread” would reduce a fair bit.