Why was Worf's klingon girlfriend pretty?

Well, Suzi Plakson is a very attractive woman, and she looked good even with a ton of latex on her face.

Of course, this same actress is one of those funny what if's ..

What if in season 3 they decided to instead of bring crusher back, had Dr. Selar take up the CMO duties?

I suspect they much like when they hired Michelle Forbes and later Terry Farrell, they gave the makeup folks the commandment to make her look alien, but not ugly.

 

That's because ugly women and gay people don't exist in Star Trek.

 

A Vulcan doctor as a regular would have been awesome and interesting.

 

Growing up, I always thought Mara in "The Day of the Dove" was attractive. And she was the first female Klingon we'd ever seen.

So you could argue that female Klingons have been meant to be attractive since Day One.

And, of course, there was Valkris in the third movie, who was clearly intended to have a certain degree of sex appeal.

 

Clearly:


but frankly, Star Trek was always about babes.

 

There were a lot of handsome Klingons and attractive Klingon women. Some looked terrible but it wasn't too odd to find an attractive one in the variety.