I'm sure Qi has taken notice of this...
Look at 2 of the people in the top 3 on 1v1 ladder:
http://warlight.net/LadderTeam?LadderTeamID=4082#1 with only 2 signature wins, one of which is over the other person in top 3:
http://warlight.net/LadderTeam?LadderTeamID=4059#3 with only signature win over alt of retiring player.
Neither is a case of manipulating the ladder (since they did not quit and rejoin after games expired), but both are cases of what can be done in a small sample size of games with the current rating system.
I am not saying they are not good players (I have personally played neither of them), but did the ladder actually test them? No
Edited 3/10/2014 15:11:15