Because he keeps some friends/parents in the farm? I would say, not only: he start to be a little annoying accusing Rick to not say to him anything.
I liked the part with Daryl injuried in the wood where his brother incites him to be more aggressive and don't be at the service of Rick. In Italian version Merl says something like "Don't be his bitch".

P.S: Glenn is really a n00b