misstery:
There was a low level legend last year who won a whole heap of stuff and was top of the earnings table for some time.
although he hasn't played since last summer his name still appears in the top 100 Legend leaderboard. He appears at number 75 and quit at level 83. (http://www.wgt.com/forums/p/79204/489258.aspx#489258)
Maybe they just find the game too easy and move on to something more challenging.
You know what is interesting, I was looking through some of the tournaments the player you referenced participated in and there were MANY sub-90 level Legends who were posting Top 5 and even Top 3 scores. I suspect that is probably because there were a lot less players in the Legend tier and many of them probably hadn't gotten to Level 90 yet.
Well, unless WGT has changed the programming of the game since, I would say that what you provided here demonstrates that sub-90 players can definitely post winning scores. It's rare but you've proven that it can and does happen.....unless that player was one of them there 'cheats' <----just kidding : )