Where I live there is plentiful water. A drought essentially never occurs. I will never have to worry about concerning myself with whether I take a 5 minute or 15 minute shower. You can imagine then, that people that live here generally don't worry about water usage as you might in a severe desert environment where water is a scarce resource.

And that's why so many applications today are giant chonks of resource waste. For a long time now we've had it to spare.

Disregarding the moral debate about resource wasting of course. That's a different discussion. The why is: we have had the resources to burn, so they do. Resource usage is as tight as it has to be very generally speaking.