A common argument in philosophy is that bad ideas should occur in the open - where everyone may ridicule them. When they are cast to the shadows they can grow, under everyone's noses, in private where only there are they allowed to exist. In private, these bad ideas cannot be challenged by others and people will be convinced to believe in them, with nobody challenging the idea as a genuinely terrible idea. It gives b…
I used to subscribe to this position, but now consider it wrong for several reasons.
First, ridicule of a bad idea will have that effect anyway - people who like the idea but not the ridicule will form and gather in niche communities to incubate whatever weird ideas they hold. This is not a bad thing, as such, and can often be productive of new cultural or scientific ideas.
Second, everyone is not a rational philosopher. Some people are easily tricked by fallacious arguments, and other people are willing to treat a threshold level of social proof as equivalent to logical validation. Hence the wide currency of 'skeptical' responses to climate change, the dangers of smoking, or evolution - for a suitable fee, you can find some people who are willing to rent out their reputation or credentials and you can then manufacture the appearance of scientific controversy.
Third, proponents of bad ideas tend to make bad faith arguments, so challenging a bad idea is treated as equivalent to trying to suppress it anyway. Of course, such weak arguments don't hold up very well in philosophy journals or social fora, but that's because people in those contexts generally have academic degrees or equivalent study and there are fairly well established standards of discourse. If someone consistently makes fallacious arguments or recycles debunked ones eventually they will be ignored. In broader social fora those institutional safeguards are absent, while nontrivial socioeconomic payoffs for the production of bad faith arguments are present - in other words, you can make a good living out of pretending to believe the earth is flat because there's a market for comforting lies that help to relieve people's existential anxieties, and the cost of repeating the false ideas is relatively low compared to the cost of debunking them over and over.
Also, you keep making non-sequitur arguments, going from claiming that bad ideas will fester unnoticed in private spaces to slippery-slope 'you're next' arguments within the same paragraph. The latter does not follow from the former, and in fact implies that it is not possible to distinguish between good and bad ideas and that if bad ones are driven to the margins good ones will suffer the same fate despite their merits.