In Empire's list of top ten best Trek episodes (all series) GR only had solo writing credits for two and shared writing credit on two more. A documentary I watched on Star Trek a couple years ago made mention of how unreliable he could be with writing/revisions, and on a few occasions someone (one of the producers I think, can't remember who) had to go and stand on his desk until he got it done.Just try writing something better than what he wrote or as good. You're barking up the wrong tree.
Mr Roddenberry may have given us something that we've all come to love and cherish, but he was only human and as flawed as the rest of us so it's best not to put him on too high a pedestal.