In the world of “stack overflow is unfriendly to new users”, banning a person providing an answer that other people have found helpful seems to be a suggestion that would take SO in the direction of yahoo answers.
Stack Overflow’s approach appears to be all answers are acceptable. This isn’t just for the person who asked the question but everyone else too.
If a person is not providing good answers and people are down voting those poor answers, there is an automatic answer ban in place... but that requires people to down vote poor answers.
No. SO absolutely can be opinionated about what constitutes a good and a bad answer. SO's job is to get to the right and most helpful answer fast. You can't always rely on the community to root out bad actors.
The mechanism that SO uses for sorting answers is community votes. That poor or incorrect answers get up votes is a problem. SO only has its community to do that sorting. The corporate and diamond mods have specifically stepped away from doing this except in the most egregious and disruptive cases.
Stack Overflow’s approach appears to be all answers are acceptable. This isn’t just for the person who asked the question but everyone else too.
If a person is not providing good answers and people are down voting those poor answers, there is an automatic answer ban in place... but that requires people to down vote poor answers.