Mario de Monti wrote:
Since those comedic episodes all came in the second season of TOS, maybe Roddenberry & Co. tried to reach a broader audience with that approach. They constantly struggled to keep the show on the air, so they may have even been "urged" in that direction by studio/network officials. Just a possibility of course, that I´m sure someone here can confirm or deny.
That's what I always figured as well. The comedic episodes are my least favorite as I'm not a fan of comedies of any kind.