Men = I believe men do want to get married however now a days they prioritise their career (previous generation they could earn a family wage but now even taking care of your self is hard) and they enjoy their personal freedom. Also whats the main benefit to getting married? Access to s*x and children which is readily available and does not require marriage.

Women = Since entering the workforce salary is effectively halved since we have double the number of workers. Those women you see that are older and remain single are usually educated and they can't accept a man of their equal even though they want equality. They believe they have become successful career women and men will find that desirable however thats now proven the opposite. They need to broaden their horizon and look at men they traditionally would not even consider.

There are many other factors but these are the key ones that come across to mind.