Looks like a classic example of "If it ain't broke, fix it until it is."
I've never served in the military or NASA, but it seems to me that in such an organization, the uniform needs to convey quickly and easily what rank you're talking to. Those pips on the badge utterly fail to do that.
"Are you ogling my chest!?"
"No, ma'am, just trying to determine your rank. >gulp< Captain."
(For my money, Enterprise had the best uniforms {and overall aesthetics} of any show in the franchise.)