Well, they were working on it innit? The Federation was young (I'm talking about TOS here strictly) and working hard to prove itself to the galaxy. And they met people who were further along than themselves (like the Organians.)
But really, you've got to understand it in the context of the time it was made in. Kirk and Uhura kissing was a big deal https://en.wikipedia.org/wiki/Kirk_and_Uhura%27s_kiss
Well, they were working on it innit? The Federation was young (I'm talking about TOS here strictly) and working hard to prove itself to the galaxy. And they met people who were further along than themselves (like the Organians.)
But really, you've got to understand it in the context of the time it was made in. Kirk and Uhura kissing was a big deal https://en.wikipedia.org/wiki/Kirk_and_Uhura%27s_kiss