The withdrawal limit used to be 50,000 satoshi for a very long time. It was only until quite recently that it was changed to  100,000 satoshi. Other than discouraging faucet abuse, my guess is that this has to do with the lower BTC price as well. 50,000 satoshi was worth about $0.25 during most of 2014. Today, 100,000 BTC is worth about $0.25 so the end result is pretty much the same.