Dude, marriage is the 'get out of loneliness free' card in the Monopoly game of life.
-- Veronica Pare and Ferrett Steinmetz, Home on the Strange, 11-09-07
It seems that it's generally seen so. I don't think I have seen a movie ever, for example, where in the end it's the right decision to not get married.
I'm sure it can be great if you can stand the knocks and you have found the really right person. But it also seems that many marriages are heck, and don't cure any loneliness.
Relatedly, I'm amazed at how many people are constantly cheating on their spouse, despite having a nice and faithful spouse. (Is it mostly men, or are women just better at hiding it?) One friend I had like that, I told about a man in my family who was also like that, and who died sick and lonely, and his ex-wife didn't even attend his funeral.
Actually I wrote it in a letter to him. He thanked me for it, and clearly he'd gotten the message, although it was not clear whether he'd try to change. But OK, you can lead a horse to water...