“This is definitely a weird feeling, but also somehow refreshing. Don’t worry. I’m not quitting Litecoin. I will still spend all my time working on Litecoin. When Litecoin succeeds, I will still be rewarded in lots of different ways, just not directly via ownership of coins. I now believe this is the best way for me to continue to oversee Litecoin’s growth,” he said.

He didn't quit from my own understanding,  he had liquidated his entire LTC balance and donated it to the Litecoin Foundation. That does not mean he quit, I think maybe the foundations needs some extra funding.