I suggest you consider how someone could know of, and understand, your suggestions very well, while still having the opinion he does. Don't underestimate other people.
Is it insane to try and keep the good stuff from disappearing under the garbage? Have you ever searched for something, only to come across a multitude of pages that were just incomplete, wrong or otherwise useless? A search term for which the gems are buried under so much manure you need all your Google-fu to find the gem? How do you think this will play out in the years to come?
People like Gruber, with an audience, a following, should set an example. If his code has bugs and he is informed of those bugs, he should take a few minutes to list those bugs. He doesn't have to solve them. He doesn't even have to point people elsewhere. Just listing them is enough and saves a lot of people a lot of time. If you can't be bothered to do that, please take your code down: it is nothing but pollution, keeping us from finding the better code.
Yes, you should take down such projects if you have been informed of problems and can't or won't take the time to document them. Infinite maintenance is a straw man, because that wasn't requested. Only some civility was requested.
Your project can cost people a lot of time if it promises, but doesn't deliver. I just spent quite some time searching for a decent XSD parser in Ruby, haveing to wade through a score of projects that promise to do what I want, but turn out to be incomplete, buggy or otherwise useless to me. Many people will perform the same quest and together a lot of time is wasted, which could have been prevented if people would not just publish any damned thing, but would also take the time to properly document its state.
Open source projects without proper documentation, I can do without. This problem will only become worse in decades to come. I sure as hell hope github will start purging old projects with too many 'not useful' votes within the next few years. Otherwise it'll be a morass of stink where the gems can no longer be found.
If that was all he did, it would be fine. But it isn't. His website still encourages people to use his script and his specification, even though they are known to be buggy. If you publish something on the internet and it turns out be wrong or defective, you have a moral obligation to point that out, especially if better alternatives are available.
That's the prime example of the naturalist fallacy. The way something is implies nothing about the way things ought to be. That we are around because our ancestors reproduced does not mean we must also reproduce. What naturally happens is not necessarily morally acceptable. Otherwise it would also be morally acceptable for me to kill your children and impregnate your wife, as happens with so many animal species.
I recall explaining this to you before. I will value your comments much lower in the future, since I will always have to watch for you being equally irrational about other subjects.