I think that that difference we draw - the line between having responsibility for your actions and not - is pretty arbitrary. I think it's good that it exists since when we're at our most vulnerable it exists to protect us from ourselves (and some people spend their entire lives in such a state if they have a debilitating developmental condition) - but it mostly exists to give all of us folks in society a good deal of comfort that if things ever go really off the rails we'll be given more of an allowance to recover - thus preventing some doom spiraling where feeling mentally unbalanced makes you paranoid about what you're going to mess up in your life which leads to more unbalancing.

And, on the otherside, we are a funny animal that takes comfort in the fact that we control our own destinies so, even if we don't - we'd like to empower ourselves as if we were in some manner. At a basic level our misunderstanding might be the fact that the ability to choose equates responsibility - without any responsibility (good and bad) your choices have no power - choosing to not do the shitty thing lets you avoid a penalty and so you can be happy with yourself. This equation of choice and responsibility is why punishment is so necessary (both big-j Justice like cops jail and the like - and little-j justice like being shunned, not getting a raise and failing to find an equal partnership in a relationship) so responsibility exists to add meaning to our lives. In fact denying it to people permanently (i.e. the developmentally disabled) does come with a strong cost to their sense of self - a lot of folks who live in support systems can struggle to define themselves, but, at the same time, neurodiversity means that different folks can find contentness in different ways.

It's all terribly complicated I think.