its been said, one is just to show your bike, and the other is to subject your bike to criticism.
the thing with the ss/fg bike "culture" (lol) there is a propensity for people to build or convert their own bikes. i could be wrong, but i think its safe to assume that ss/fg bike riders are way more prone to construct their own bikes or take something and convert it rather than going out and just buying a complete bike straight out. and if they do buy a complete, it seems they are more prone to want to customize the complete with new parts to make it their own.
and because of this, many ss/fg people build their bikes or convert road bikes or customize their completes in a less than functional way, mainly because of ignorance (not stupidity, just lack of knowledge). like wierd seat post heights, saddle angles, stem angles, stem lengths, wierd handlebar choices/setups, frames that are way too small/big etc. others want the aesthetics of customization so much they choose parts moreso for their looks, sometimes to the detriment of function. others just make clown-ish tarck bikes aimed at obtaining hipster cool points. or maybe they obtain a fancy pants velodrome specific track bike, but then never ride it at the velodrome ever and put street risers on it.
before there was the Jackass thread in which ss/fg riders could point and laugh at ridiculous ss/fg bikes.
the "what you dont like about my bike" thread is basically the jackass thread, the difference being the person has to post their own bike ;p