> "Control the things you can control, maggot. Let everything else take a flying fuck at you and if you must go down, go down with your guns blazing."
- Stephen King, "The Drawing of the Three"
Your post is wise (or at least, it resonates to my best thinking on it which boils down to the serenity prayer as well.)
But I disagree that the two things in your first paragraph are equally bad.
If you think nothing is in your control and just blame others all the time - then you pass up every opportunity to make your life better, and I agree this is extremely common.
If you are on the other extreme and think you can control everything - you do end up tilting at windmills and wasting a lot of time and energy, but you also end up doing things that make a real difference in your life. It's a strategy strictly dominant to passivity.
Thus blaming others is always worse and I agree with your paragraph #2 and #3.
Your point is well taken. There's the other side of the balance" - the factors outside of one control define the ceiling limit of your delta change [0]. Of course, you can ask people to focus on the controllable and ignore the things one can not control. However, the fact that the family/country/skin color you are born determines pretty much most of your fate is not easily accepted by everyone. And rightly so, they have every right to be aggrieved about it.
[0] https://www.pewtrusts.org/en/about/news-room/press-releases-...
Blaming yourself, or at least thinking what you could do differently, is the sane default when something goes wrong.
"God grant me the serenity to accept the things I cannot change, Courage to change the things I can, and Wisdom to know the difference."