The good thing about starting a business where there are reputable companies established, is that you know there is a market for this particular service/good. The negative aspect is that there is competition. You just have to make your business different or better in some way. Research what those companies are doing right and what they are doing wrong and work off of that. Most new businesses are not started from scratch but from working off of other ideas to make them better (e.g. Google, Facebook).
I agree, nursing experience won't be as helpful but it is definitely not useless or impossible. I think that this idea would work, or even student housing for health professionals.