Yes, Bella, you have it right. Unfortunately, so many will take it wrongly.
Of course, what you say is true, because fundamentally we are all selfish. No, I'm not demeaning everyone. It is simply the reality that our psyches demand that we protect ourselves. Sadly, in some cases, that means that our minds - our unconscious or subconscious, causes us to 'blame' others for our own transgressions.
Any keen observation of people can evidence this.
However, 'blame' is not only unproductive but also detrimental to those who choose it and those to whom it is attributed.
The reality is that we are all victims of our own being, imagination, experience, character and above all, innate instinct and urge to survive.
I believe that human beings are inherently 'good', (though I don't really accept the common notion of 'good' and 'evil' or such.)
Life and living is a complex experience and none of us, in my view, are born with any inherent and/or particularly adept ability to understand or deal with it. What we do receive, in common with all animals and probably all life-forms, is an undefinable force to live. Of itself, this is essential for life to survive. However, it has no moral or ethical qualifications. Those are human constructs, learned, taught and predominantly conditioned by culture, schooling, peers, parents, society and so on.
The saddest part of all this, of course, is that some of us choose to 'blame' for that is what we are conditioned to do. Instead of using that amazing and wonderful facility we have - the intellect - to consider the what, why and wherefore - our instinct so often takes over and we do, say or act, in whatever way it tells us is necessary to survive.
For me, that is the sad paradox of being human - that amazing and wonderful ability for compassion, caring and empathy in a being ultimately governed by an instinct to survive at any cost, even giving up all of those better characteristics.
It is, for me at least, what separates the real human heroes from those commonly assumed to be such - even though they have suffered and lost for the sake of others.
Of course, this is just my take on your post. I don't claim to be 'right'. It is simply my understanding right now.
Take care. Stay safe. ☮️