Humans are inherently lazy and do a bad job of associating today’s bad habit with tomorrow’s bad luck. The same basic reason they don’t want to encrypt every file they own is the same basic reason they get fat and are unable to shed the weight.
Without motivation no habits will be changed. I would have thought the Snowden leaks would be sufficient, but for some dumb reason there’s still a strong current of “well I have nothing to hide, who cares??” style thinking.
I guess until people are actually damaged in some way that they are forced to confront, adoption will be limited.