Playing Pretend?

The German language is sometimes quite strange.

Today in my German lesson I learned what the various pieces of clothing are called.

For instance, the word for "suit," meaning matching slacks and jacket, is der Anzug.

But then I discovered that der Anzug is used only when talking about suits for men.

Suits for women are called das Kostüm.

My tutor didn't understand why I found calling what women wear to work a "costume" a little insulting.