Well said @henryclive.
I was going through the topic and reading these entries . Ah after long time I am back in game. What I understood is @xiao-aine doesn't believe in marriage or just don't want to get married. Whatever it is.
But I want to let @xiao-aine know that not in every religion and especially not in religion Islam it was for purpose. As I included not in every religion I meant to say origin of Christianity and Judaism etc. but slowly the marriages are becoming like you are saying, I admit nearly in all religions it is happening even in Islam.
But there are good ones too, to give as examples.
The question why to marriage is having two answers from now;
First is, because to not die alone, to have someone who give us Respect after the death, who remember us after our death. Who can tell life of ours to the rest of generation and the process will go on.

Secondly this is the purpose of life, the man and woman are made for each other, if we are going in the other way to use this, like going to bars, pub, clubs etc we know what's happening out there, for the time we are for sure, getting us out of tensions, questions, too much care, etc. but after we spend our these ten or twenty years, we will feel that we are alone, this all was the young blood's curse we faced. But the life will not changed then, and what spent was past. Maybe I made some points. Sorry my English is not well to understand but.....