I am in a relationship and I enjoy doing those things alone. I like going to the cinema alone, I shop alone etc... I was always a loner as a child. And if I hadn't met my fella when I did I am positive I would still be single now.
I like being on my own for the most part. Don't get me wrong I am glad I have my O/H around and he has been with me a long time now but I also like my own space. In response to childhood trauma, I had a pretty crappy childhood and I do honestly thing that has resulted in me being who I am today. I am strong minded, confident, don't rely on people in general. But at the same time I find it very hard to make friends and I am the least tactile person I know. The way we are brought up doe shave a big effect on who we are now.
But I don't see anything wrong in people wanting their own space and time.