A lot of people came out after homosexuality was decriminalised.

Freedom of religion allowed a lot of people to express their religious identity which was formerly suppressed?

A bit of an obscure example, but: Capoeira was forbidden in Brazil for a very long time, mostly because of a moral panic(for brevity I'll leave the complexities of this situation out of this comment), then when it was legalised, and the stigma around it began to disappear, it quickly became very popular, both in Brazil and internationally!

This seems to be to opposite of the example GP was seeking. Unless you mean to say that a great many people (both in Brazil and internationally) were already practicing Capoeira before it was legalized...

Left-handed people.

Most sinister[1] example

[1] See notes on etymology etc. at https://www.merriam-webster.com/dictionary/sinister

I bring this one up every time someone brings up Chesterton's Fence arguments about stuff like this.

Why was left handedness considered taboo and evil? Do we need to figure out a legitimate reason for this before we can remove the fence? Could there possibly be a legitimate reason for something that clearly absurd?

I mean the point of the argument is to try to find out if there is possibly a legitimate reason, not to assume there was and not explore removing the fence. Sometimes no there was no good reason. Sometimes there was but it’s no longer applicable.For example lots of religious dietary restrictions have reasonable health benefits, especially in a society before modern refrigeration and food safety standards. So while there was a legitimate reason, it’s not nearly as applicable anymore. Discouraging sexual freedom and promiscuity makes a lot more sense in a society without birth control and where every additional mouth to feed means someone isn’t making it through the winter. Less so in a modern society. And sometimes there are absolutely legitimate reasons that have just been lost to time (most commonly captured in the idea that most safety rules and regulations are written in blood)

No comment about Chesterton's Fence but I have heard (but never confirmed!) one reason for left-handed stigma is to do with hygiene. The idea is that before modern hygienic standards (e.g. sinks with soap in every bathroom/kitchen), the left hand was reserved for "dirty work" (we are also considering a time before toilet paper...). So for example when you reach out to shake someone's hand, it would be rude to use the left.

Your right hand is your sword hand; by offering to shake hands, you demonstrate that you are not about to run your counterparty through.

This is apocryphal

There could be, but I think the presumption should be that it is normal social evolution to stigmatize minorities. Red-headed people, Jewish/Semitic people, people with cleft palates, on and on.

There seems to be a representation threshold below which any observable minority is considered undesirable. To the extent there is a “legitimate reason” it is probably rooted in evolutionary psychology for avoiding too much genetic variation in small tribes. I submit those fences are the opposite of Chesterton’s fence and can happily be ignored in today’s society.

> evolutionary psychology for avoiding too much genetic variation in small tribes

Hmm. I suspect it's just "other tribes". We humans will make tribes out of literally any distinction, even athletic team preferences. It's kind of our thing.

> Could there possibly be a legitimate reason for something that clearly absurd?

Yes: https://www.straightdope.com/21343459/in-the-third-world-do-...

For me, the Chesterton’s Fence principle doesn’t insist that there’s a good reason for everything that needs to be discovered. It says, don’t remove the thing until you understand why it was put there. If you’re sure there’s no good reason, go ahead. But find out first.