Hmm

It's clear that all the homeless people in your examples simply lack this quality; they don't have the necessary level of self-awareness.

And what do you think they're doing when they get drunk or high? They're trying to suppress that self-awareness. But between sessions, there's sometimes a window when they realize how miserable their existence is. And instead of interrupting it, they go for another dose – that's their weakness of character. I understand that you have a high opinion of yourself, but believe me, you don't need to have a complex spiritual structure or unlimited intelligence to realize that you're at the bottom and that it won't get any better.

But following base instincts can't be called courage, because it's just the simplest instincts in one way or another.

Exactly. And the instinct for self-preservation is one of the strongest. So draw your own conclusions.