yes it is. One of the worst episodes of TOS and in all of Trek, and a surprisingly conservative a commentary coming from the show at the time.
Its reputation notwithstanding, Trek
was not nearly as liberal at times as people make it out to be.
It could have been worse. Yes, the message is kinda, "See? We warned you. Time to grow up now." And frankly that's realistic. You can't dance in torn sheets in the rain forever. Growing up doesn't mean selling out.
But at the same time, Kirk remains remarkably restrained...Spock is sympathetic and gives that bit at the end about finding Eden.