It's very hypocritical of those that call anyone who sells an equipped item an "idiot" or such. Are you telling me that not one of you has never "not noticed" something? Yeah right. You might want to go a little easier on other players, because when you insult them, you're insulting yourself as well.
I am very much in favor of a gear lock. The sheer number of threads on this topic and mentioning of it is proof that it matters to many other players as well. It sounds like very simple coding as well. I would hope that Blizz would re-consider some action on this.