A common feedback : "My friend XYZ just signed up, why can't I find them in the player directory?"
Until now, anyone who has made zero moves (typically a new member) did not appear on the directory. This was to filter out those who sign up and then proceeded to never make a move. (It happens more than you would imagine!)
In some cases, as in the example above, this isn't desirable though, so now "zero move" players can be included in a search using the non-mover toggle switch.