My grandma and grandad were married for 65 years. He was very ill and knew he was going but clung on to life so he could see their 65th anniversary through and passed away a two days later. In those days, things were made to last. They were taught to "made do and mend" and I think they worked through/put up with a lot of their problems, and for financial reasons it was better. Plus divorce was heavily frowned upon, even shameful.
Nowadays, if you look at a lot of things in society, things in general have a shorter life span, they're changed a lot and got rid of. Relationships break up easily over sometimes trivial reasons and a growing number of people don't want/trust that a marriage will last till the day they die and they don't wanna be tied down.
Marriages can be a lot of hassle too and very expensive, although my brother chose to go to Sardinia with just his bride and her daughter.
I think I would like to get married, especially if we were going to have kids but my mum has been divorced before so it puts me off a bit