It simply comes down to some posters having the opinion that if it happens in Trek they like, they try desperately to explain it. If it happens in Trek they dislike, they act like it's a deal breaker.
Yeah, there's a bit of a double standard there. Wrath of Khan is full of plot holes and pseudo-science, but it's still the best Trek movie ever. And Spock's very existence is an absurdity that puts underwater starships to shame, but who among us would want to do without him?
(I mean, seriously, a green-blooded, copper-based alien lifeform can breed with humans--despite a completely different blood chemistry? And people balk at building starships on the ground?)