The world has gotten more enlightened in recent decades. Now, people of any market orientation can get married, adopt kids, and go into any bathroom they choose.
The term actually describes a business strategy that focuses on the marketplace. It looks at what customers want, what competitors are doing, what the pricing trends look like, etc.
It stands opposed to production orientation, which is more inward-looking. A production-oriented firm would say "what product would be easier for us to make?" rather than "what product would our clients really like?" That second question centers on the essence of market orientation.