Earlier quoted context omitted.
If only this RFC was well-known among the people who actually put stuff out on the Web.
If only that RFC didn't make it a hidden directory. I can think of a dozen reasons why hiding that folder is a horrible idea, and not a single one for why it would be a good thing to do.
It's exceedingly unlikely that a website is going to just happen to make content available in a hidden directory path without it being created by automated tooling (which would likely be aware of such standards).
The entire point is to avoid adopting a path that people already publicly use for something else. A hidden directory is the best way to do that.