The reason you haven't seen a cedar wood floor before is because cedar is way too soft to make for a durable floor. It's so soft that it's the only wood (that I know of) that you can leave a mark in using just your fingernail.
So, you can expect to leave permanent marks on your floor if you drag furniture across it, or probably even move your bed to clean under it.
Years ago, when it was common to have hardwood floors, people would often only use hardwoods like maple and oak on the the main floor of their house; where the living room and dining room were located and where all the entertaining of guests took place. On the upper floors, where all the bedrooms were, they would often opt for fir flooring to save money. After all, people typically wore socks inside the house and went barefoot at night, so the wood on the floor didn't have to be hard to stand up to dirt being ground into it's surface underfoot. So, I'd say the softest wood you could reasonably go with in a bedroom would be fir.
Cedar is an attractive wood because much of the cedar we see is clear (no knots, or only small knots). So, it looks like it would make for a beautiful floor, and it would probably initially look great. The problem is that cedar is such a soft wood, that floor would be very easily damaged from scratches and dents, and it wouldn't look good for long.
It'd be like using ordinary latex wall paint to paint a floor. The paint would be so soft that dirt would get embedded in it underfoot, and the traffic lanes would start showing as dirty areas on the floor before you knew it. And, even though the floor would look dirty, you wouldn't be able to remove the embedded dirt without also removing the paint, so ordinary sweeping or mopping would be ineffective. The only way to clean the floor would be to scrub the dirty surface layer off. Basically, it would simply be a very poor choice for a floor covering. You'd get similar results using a very soft wood like cedar on a working surface like a floor. Anything you dropped on that floor would leave a dent, anything you dragged across it would leave a scratch, and you couldn't walk on it with shoes because that would cause dirt to be embedded in the soft wood. And, a hefty woman in high heels would wreck that floor.