I think part of the reason why the "two many female characters" and also the writing in general being bad popped up is because Roddenberry didn't have much of a history of writing interesting female characters. Not only that TOS basically revolved around 3 characters and some say two in just Kirk and Spock. On TNG though he had a ensemble and he wasn't going to just make them bit players like Sulu, Uhura, Chekov and Scotty to a lesser degree. Roddenberry also I guess hadn't written much of anything for years.
He was basically a has been who was barely a was been even when he was something. While he actually had decent writing experience going into TOS it seems TOS was his only lasting creation. Well and TMP. It's really weird how he got both a second chance with TMP and third chance with TNG only to be replaced by better talents carrying on the franchise afterwards like Nick Meyer and then Michael Pillar and yes even Rick Berman.
Jason
He was basically a has been who was barely a was been even when he was something. While he actually had decent writing experience going into TOS it seems TOS was his only lasting creation. Well and TMP. It's really weird how he got both a second chance with TMP and third chance with TNG only to be replaced by better talents carrying on the franchise afterwards like Nick Meyer and then Michael Pillar and yes even Rick Berman.
Jason