Let's be sure of what loneliness is or is not. When you're a private person, an introvert or a loner, you're not necessarily lonely. A lot of us need our me-time or alone-time once in a while, some more than others. Loneliness however, is more deep, more psychological than social.

Loneliness is a constant lack of contact with other people, even when the person wants to be. It is the feeling of isolation, when you find it hard to make a connection with a special someone for intimacy, including physical and emotional.

http://www.mynewhitmanwrites.com/2013/02/is-loneliness-reason-to-get-married.html

Indeed, many people get married because loneliness makes them desperate. However, feeling like that makes one more likely to make poor love choices and they could end up in unfulfilled relationships. Marriage is not a magic pill to cure loneliness, if you did not make the connection with your spouse before you got married, it is unlikely that a wedding will do the trick.

Eida one ȋ̝̊̅§ an introvert or an extrovert loniless ȋ̝̊̅§ neva a reason to get married. There r a lot of married pple dt r still LONELY.

Never.

OP,i beg to differ on ur opinion that loneliness is more psychological than social. Actually,the reverse is truth.Being lonely means having no friends to talk to which leads to unhappiness.

Now,let's be realistic here,
''then God said,it is not good for man to live alone.I will make a suitable companion to help him''(Gen 2:18).
So,from the onset,the first reason for having a companion/getting married was to avoid loneliness.
And people still tie the knot for that reason.
Though not a sole reason that guarantees happiness,but it is a good reason to get married. #candidme.