Why do women wear have to wear make-up if men dont have to?

In some cases women are forced by law to wear make-up. (Jespersen vs Harra's Casino)

even though...

Title VII of the U.S. Civil Rights laws forbids employers to discriminate against people because of sex.

I didn't know it was a job requirement in some places.
I think it's terrible...

Uh.. when I was dating, I specifically asked my gf's NOT to wear makeup.

It tastes AWFUL!

Women wear it to excite men. Men don't wear it because women are not attracted to men for the same reasons.
The laws you are stating are laws that allow private institutions to try to make things interesting for their customers. Otherwise they would be forced to have 400 lb wheel chaired ridden women playing Tarzan in movies with out being sued.

Maybe to make them look more appealing. I personally dont wear makeup that often. Well except Dr Pepper chapstick, but I dont think that counts.

Well, Kieth, doesn't that depend on your definition of make up?

I wear aftershave and, on occasion, Cologne. I use a styling gel on my official police mustache. I suspect you use all kinds of gunk in your hair (alas, not my problem anymore). I even use hand creams on my poor chapped mitts.

Male grooming products might not be as varied as women's stuff, but it's still "make up".

That case you are referring to is about Harrah's Casino wanting women to wear make-up to work there.
First off its a Casino. Having attractive women and men working there will bring more dumb rich people there to waste money. This was backed by NCLR. That just tells me its full of hot-air. Just because Darlene Jespersen couldn't look butch she complained. Just go to any job place and they all want you to wear or look a certain way.

I think the question is why do women have to wear make-up while men do not.

Modern women have been brought up in an egotistical, male chauvinistic, marketing driven world and have not really discovered individual freedom. They have been conditioned by marketing/society that wearing make-up is the way of life. Women are taught to love make-up and feel insecure without it (be delusional). This is a very serious problem that is causing physical and emotion abuse to women. A way to make women out to be objects.

Men, well there really is not any marketing campaigns targeting men to wear make-up. Marketing is putting out the image they just need to smell good and regrow their lost hair.