Well, that would make Kirk one cold and callous bastard when we see him back to his cocky self later on, now wouldn't it? At the very least, it'd be tough to continue to command the same level of respect from Spock and McCoy if Kirk was willing to flush their asses down the cosmic toilet for the sake of some 20th Century mission worker he'd just met.
Are you kidding? That is the friendship capable of surviving everything.
Hey, if Kirk's crew can trust him after ENEMY WITHIN, anything goes.
But more to this case, if you haven't met somebody who for a time you didn't think was worth losing everything for, it is IMO your loss.
The coda at the end of THE WIND & THE LION kinda echoes this (as does REQUIEM FOR METHUSELAH) ... The Connery character Raisuli has committed a huge bluff with kidnapping of an American woman with the intent of embarassing certain folks, threatening (never seriously) to kill her. Ultimately, he returns her after some mutual respect earning, and she in turns saves him, but his whole way of life is destroyed by the intrusion of western imperial forces (well, it was on its way with the start of the 20th century anyway.)
At the end, Raisuli is with his second, at a beach, and the guy says, it is as you said, great raisuli, all is drifting away on the wind, we have lost everything. And Raisul replies, have you not once found something worth losing everything for? (then they share a hearty manly bonding laugh and the credits go up.)
Actually seems more like that MERCHANT parable in EMPATH, now that I think about it.
EDIT ADDON: this might be more interesting than the thread that got closed in lit on this subject, which is saying a lot.