This strikes me as a somewhat unfair characterization of many of these communities. In my experience, a much more common issue is that the people who do have answers end up ignoring the group and it becomes pointless. It rarely becomes a source of career hindrance or long-lasting judgement, it just ends up being useless because there's not a lot of incentive for the expert side of the equation.
People who are likely to judge people for dumb questions are rarely involved in those groups in the first place, for exactly all the obvious reasons.
The more realistic outcome isn’t that your boss ends up a drunk puking slob (and for what it’s worth most of these groups don’t include leadership anyway, so not sure why anyone's boss would be involved) but that an intern floats a terrible idea ("I'm thinking of taking these 10 shots of 151"), nobody responds, they take silence as approval, and they end up causing a mess and then being judged for the mess they caused.
A quick gut check from them with a healthy group might get a few eye rolls and a "here's why that's a bad idea", but not any lasting judgement unless they completely ignored the advice.
The only case I can think of where that might happen is if they already did something which has policy or legal implications ("hey i accidentally dumped the whole user base including PII to my phone"), in which case - good? There should be a review mechanism, including consequences if they ignored a bunch of roadblocks.