What is painful for you, may not be painful for someone else. I know plenty of people that have spent their lives without romance. It's such a weird concept for me to grasp because I don't think I could do it. I love having a partner and someone to come home to. It'd be hard for me to make it through my life without someone to share it with.
There are some people in this world that would prefer to spend their lives alone. So long as they are not doing harm to themselves, I really don't see an issue with it. If anything, I think being just friends with multiple people could have it's benefits. I wish I had the ability to spend more time with myself and less time with my romantic partner. It'd save me a lot of heartbreak.