Kind of tradition....like putting (long-pics included) in the subject.
Obviously being an RV forum many posters are on the road in a CG somewhere, and using whatever Internet access they have to read emails and stay connected. Some use 3G or even 2G cellular, maybe even dial-up from the CG office. Think back when the forum started or even just a few years ago, not many CGs had wifi and mobile Internet was not very fast.
Nothing worse than being on a slow connection and opening a thread that is 10 pages long and loaded with pictures....then having to wait (and pay) for it to load.
This becomes less of any issue every day as 4G gets built out and wifi becomes more ubiquitous....so the "sorry, long post" is somewhat of an anachronism...
However, I have noticed that many posters here don't take the time to read a long post...over and over I see someone post with a problem, only to have multiple respond suggesting that the OP try something that they already said they tried.