I feel like personal responsibility is one of those things that work nice on paper, but that requires forethought, correct information, good education, processing power. Then there's things like genetics, bad upbringing, peer pressure, propaganda (adverts), etc... which all subvert those. Human beings are not rational actors who can be expected to make optimal choices even most of the time. Even if we were robots in the sense of a computer program we would still have to deal with limits to complexity, information and processing time. Exerting restraint and self control is known to take time and energy, energy which is in limited supply and requires replenishing through intake of calories.
That's life, though. People have different information, different education, different intelligence, different upbringings, and they make different choices than you or me. I make the best decisions for myself given my experience and situation, and you do the same for yourself, and everybody else does the same for themselves. I'm not going to force my choices on you, and it's not your place to force decisions on me.
Nobody makes the absolute best decisions every single time, but in general they certainly make better decisions for themselves than a stranger.
