I don't really think it's possible.
All you can do is be an example and lead the way by being yourself.
What is the phrase 'Change the world starts with you'? Or something like that anyway.
As a very direct person myself, I have had many a confrontation with people with tunnel vision affliction (that sounds really good if you say it out loud btw! haha) and honestly, it hasn't helped.
The only way there is even the slightest possibility that they can 'change' is if they really want to and are triggered by some positive change they can see in someone else.
Regardless, I understand your frustration and it is very valid.
Yet that's spent energy you could put towards better use for yourself (which in turn is for them although they don't see it yet)