Why don't people in Xining use water fountains?

On the one hand, it's because they're poor, and on the other hand, it's because they haven't been exposed to these new things

I don't think that being poor is the main thing, but the key is whether or not it's necessary, because there's very little pollution in Xining, and unlike in other places, there's no problem even if you drink the water from the tap.