MrMind's "position" was not usurped for the simple reason that there was never any such "position" in the first place. Anyone can create an open thread on LW if they do it before anyone else does; in this case, Clarity was the one who created the thread first. Downvoting the thread simply because it wasn't opened by your "preferred" poster is both petty and impolite. It's not like it really matters who posts the thread anyway, and there are far easier (and less ethical) ways to get karma than posting an open thread.