Other people are always impacted by our decisions. That's just the world we live in. Damn near everything you do affects the people around you in some way.

Do the people around alcoholics consent to that?

At some point the risks/reward of various behaviors (let alone the substances that enable them, you don't see people scrambling to ban belts because people hit their kids with them) are such that legislating away things with varying degrees of state violence to back it up isn't worth the tradeoff.