Yes he needs to focus on developing the talent he's got at his disposal rather than trying to win points against those who have dared to criticise him. Does himself no favours when he responds with those kind of comments.
All he does with those comments is ensure an even louder response the next time we draw or lose. If you want to let your play shut up the neigh sayers, then you best keep your own mouth shut.
No manager is bigger than any clubs fan base, and nothing good can come from him escalating this row with the fan base (however “deluded” or sane they may be).