I always looked at AU58 as a coin that would be a gem (MS 65+) if it didn't show some very light circulation rub. A MS 60 would be a coin without circulation rub but with many contact marks and poor eye appeal.
I would much prefer an AU58 with barely visible wear, than a baggy, marked and lusterless example MS60. But, as the article says, this would not be a factor for those only in it for registry points. I guess those few extra points outweigh the lack of eye appeal. JMO
My experience is much like expat above.........'60s tend to be baggy or ugly, where '58s can be most beautiful with minimum wear and retention of lovely luster.
To be honest, AU58's can be ugly too. You could always just take a 60 and rub it over a rough cloth a bit.