Which is fine for real people, but it seems out of character for a scripted regular. But it was early in the series' development and Bones was a little crankier.
There's a sense in which the earliest TOS episodes were a little more sophisticated than the later, polished ones. Before the actors got their egos fully invested in fictional identities and these characters took on a life of their own ("My guy would never say that, re-write it!"), there was a rough-edged naturalism to the dialogue, with raw, unflattering emotions coming out more often.
In this light, you could say that Star Trek
followed the opposite path of Battlestar Galactica
. Where ST began with some rough and raw naturalism and evolved into idealized romanticism, BG's original series was romanticised while the Ronald Moore remake went to extremes of naturalism.