In some parts of the country, particularly in areas with basements, wringers remained popular for decades after automatics came into being, and in fact some folks who were accustomed to wringers either had difficulty or never did fully or successfully make the change (which actually netted Robert a couple of nice low mileage vintage automatics for his collection, as memory serves!).
Also, they were generally about half the cost of automatics particularly in the early years (we can probably credit Sears for making automatic washing affordable to the masses beginning about in the 60s), so they were probably purchased by families with tight budgets, particularly when combining the cost of the washer with the additional expense of plumbing and installation in a home that was built before automatics.
Then too, some depression era folks I'm sure thought the automatics were very wasteful, where they were accustomed to using their wash and rinse water for many successive loads, hence the popularity of suds saver automatics for many years.
In Minnesota, it is not at all uncommon to find wringer washers present at estate sales and such. There are people who insist that no automatic washer can clean as well as a wringer. If you're line drying, you can actually get your wash out a lot faster with a wringer, the catch 22 being you have to be there pretty much the entire time attending to it. You would lose the time savings using a dryer, since you'd get all your wash done and then have to wait for the dryer to work through the backlog anyway.