I think people mistake two words for each other. Lonely and alone. We could be in a huge crowd of people that we know and feel very lonely. But we could be by ourselves and be alone and feel contentness with ourselves. I think the problem comes when we choose to be alone by ourselves more than we want to be with people. So alone time is good to gather our thoughts, calm our inner spirit, to pray, and sometimes just to cry at the unfairness of life. So I think embrace your alone time to strenghten yourself for the time that you spend with other people. Society wants everybody so busy all the time, so for someone say they need to be alone they don't know how to handle it. Scripture say "Be still and know that I am God". Christ also went to be by himself t pray and to gather strength in what was coming so we could follow His example and do the same