What do you mean with "hurt" ? Keep in mind that I'm not familiar with playing a lot of ladder games, hence the question.
The 1v1 ladder uses a ranking system called Bayeselo which takes into account the performance of your opponents
after you beat them. If Player A beats AI (or worse yet, loses to AI) and AI's rating tanks because Niklas abandons the account, then Player A's rating's going to get lower too. If AI dips by, say, 50 or 100 points, then Player A's rating's going to dip a bit too because they either pulled off what now looks like an easier win or they lost to what now looks like a significantly weaker player.
This is one of the reasons you shouldn't use multiple accounts on a ladder- you can't do this on your main account since its rating would tank, but if you decided to use an alt to get your opponents' ratings to tank while you kept your own rating up, you're pushing everyone else down a bit and potentially making your rank a lot more secure.
If AI/Niklas decides to tank AI's rating, Jefferspin gets screwed pretty hard since Jefferspin has a loss to AI.
Edited 5/12/2016 23:49:17