It depends on the person...and I disagree that its always easier for men. Single men can be loners that have little in the way of a support system (which is ok for loners, hence being loners), but everyone needs support at some point in their lives. Single women, on the other hand, can have a great social network of friends and/or family that make them quite content and happy. Their "stock value" doesn't go down as they get older, in fact it goes up as they become more independent, more needed by others, and more engaged in their community.
I think (and hope) the days of the concept of the "lonely old spinster/Eleanor Rigby" are over. You are just as likely to find lonesome sad bachelors these days. Each gender can be single and unhappy or discontented. Each gender can be single and happy and content.