All male organizations tend to function better than ones that mix males and females. Females are a major distraction and a source of tension for males. Males are far, far easier to control and command where not females are present.
You know, as a woman, this kind of attitude pisses me off. And it's just as annoying to hear it from an American as to hear it from an extremist who thinks that women should be covered from head to toe because she might "tempt" a weak man. Women end up being the victims of discrimination because of insecure twits who can't interact with them properly or can't control their raging hormones or whatever.
If some men can't control themselves around women, perhaps THEY should not be in the service (or around the women,) instead of denying women the opportunities that the service gives to them.
Also - Sex is is a normal part of life, Dayton3, as is the mixing of the sexes. I will grant that shows like Enterprise approached it the wrong way, going for the immature titillation angle as opposed to showing a mature relationship between a couple.
Star Trek stories are ENRICHED by character development. Battles and fights and ships blowing up might add interest to a story, but it's how people react to things, how they grow and develop or how they learn from mistakes (those they make or those of others,) that makes a story interesting.