Or they believe the costs are worth it. Trying to convince people to support extraordinary lifestyle changes requires extraordinary evidence that the net result will be positive.
The costs are more than likely paid by others, which is why they're oblivious.
Far easier than convincing them would be to stop subsidizing them, sprawling car dependent suburbs are a giant money sink that the people living in them rarely pay for.
You're likely reading this on a device that was invented while plenty of ignorant people were still not enlightened.
(I admit I may have worded my comment a bit better with a "that" - 'If innovation can't happen until the ignorant are enlightened we're never going to see that innovation.')