IMO.
People who sell, invariably, replying to a thread, will post items for sale. Unless the thread is Aussie hammer or Val Lewton, or Hell drivers, then its probably a safe bet that anything I post I am open to sell. Saying that, I post for interest sake (like the above westerners). Items I have, others might not have seen, just for fun and information. I assume that if someone sees something they like and want, they will make a comment like WOW I MUST GET ONE OF THOSE in which case I can message saying OK, its $10) or they will message me. Thats not the 1st priority of the post, but might become a nice bonus.
So, while I don't find the word "selling" put in the post, I do think its redundant, if I wanted it, I would let the post-er know.
But for me I don't get it why people get up in arms about it. I haven't dealt with ozcinema (I don't think so anyways) but from what I gather he is a pretty dedicated collector and also a dealer, which you will find is like most people who post on forums differing levels of dealing of course).
Anyways... I guess a Gunfight at the O.K. Corral is apt.