If it was kept civil and on topic I'm sure very few would have a problem with that. However, it is rarely civil and never kept on topic!My issue with locked sale threads is if the description is misleading. Someone posts Juliets with ruby lenses and red rubber. Describes them as "X Metal finish, ruby lenses, red rubber, tight, like new, lenses and rubber are mint. $450."
And then they lock the thread. Lenses look after market. Rubber looks like linegear. I hit the back button and don't look at them again. But some new guy that wants to try out xmetals sees them and assumes they must be oakley lenses and rubbers, due to the price. He buys them. Or maybe he asks the seller a question about them and gets a vague answer that could be interpreted as they are original lenses and ducati rubber. Then he buys them. Eventually he realizes his lenses suck and finds out they aren't real.
If the thread wasn't locked, people can ask questions and force an accurate description out of the seller so a potential buyer is informed.