Here is a guess: the fridge that lasted 50 years cost a months salary, while the fridge that lasts 10 years costs 1/5 a months salary. So you get exactly what you pay for, and you pay exactly as much for "having a fridge" today as you did when they lasted 50 years.
But here is the kicker: a) People don't want to pay big money for something they don't know will last 50 years,.
b) People want new things. While it's convenient to not have to replace something for decades, they also want to remodel their kitchen efter 10-15 years, at which time thet fridge needs replacement anyway (in 2000 it was chrome, in 2010 it needs to be black, etc).
That said, it would be good if the people who want new things could sell their old ones, instead of throwing them away.
Perhaps it would be better if people buy refrigeration as a service. Then the service provider can worry about such things as lifetime, maintenance, replacement, and selling old refrigerators.
And there would be no incentive for "planned obsolescence".
I think this will very much be the case of a lot of things. People will "own" less things and instead lease. It's a trend in cars, and I think more and more things will go this way. I don't want to make big investments and I don't want to maintain things (which means they own me more than I own them). Repainting the house or worrying about the lifetime of my boiler is exactly the kind of stuff I'd happily pay a big premium to let someone else do - and most importantly - worry about.
But here is the kicker: a) People don't want to pay big money for something they don't know will last 50 years,. b) People want new things. While it's convenient to not have to replace something for decades, they also want to remodel their kitchen efter 10-15 years, at which time thet fridge needs replacement anyway (in 2000 it was chrome, in 2010 it needs to be black, etc).
That said, it would be good if the people who want new things could sell their old ones, instead of throwing them away.