Originally posted by Darth Thor
But I guess issue is Teela was never really the most popular of the MOTU.
She is literally the most popular character after Adam/He-Man. She appears in every episode, and there are more episodes centered on her than any other character that is not Adam/He-Man.
She is the reason 45% of the viewing audience of the original series was female, and she is the reason a female-centered spin-off of Masters of the Universe exists. That is right, Princess of Power was originally planned around Teela.
After considering the implications of the heroine for girls being the non-superpowered girlfriend of the Most Powerful Man in the Universe, Filmation and Mattel created She-Ra, He-Man's equally-powered twin sister.
But all the preliminary designs for Princess of Power featured Teela, and even the preliminary designs for She-Ra were drawings of Teela.