The joke was that the bug could be caused because it was written FOR a woman, not BY a woman.
I wish people were a bit more careful before slinging these words around, not just because it's overly harsh but also because I consider these to be serious issues, but when used as a cudgel carelessly thrown around it devalues the term, and thus devalues the actual real problems it describes (or rather, once described, as this ship, unfortunately, seems to have already sailed).
There really is some nuance to be had in these things.
And in this instance, it's also completely unnecessary to your point. So please don't cite these types of radical sources when making innocuous points. It would be like if I was having a debate about average rainfall, and said something like, "Well, according to the UnabomberFanSite, the average rainfall is 3 inches". It's just so needlessly inflammatory and provocative that your best bet is to cut that out and replace it with a more mainstream source.
Just one example: Their information about Alcoholics Anonymous’s effectiveness can charitably be described as a dumpster fire: https://rationalwiki.org/wiki/Alcoholics_Anonymous (For example, they cite Brandsma 1980, which is a very outdated chestnut anti-AA polemics always bring out; the study is really old and its methodology was pretty bad: https://en.wikipedia.org/wiki/Brandsma_1980 )
In particular, Rational Wiki’s article on AA completely ignores Cochrane 2020, which shows that Alcoholics Anonymous has a 42% success rate: https://en.wikipedia.org/wiki/Effectiveness_of_Alcoholics_An...
For some reason, it seems there are basically no nominally-neutral websites, forums, or news outlets that exist. (That I'm aware of.) I don't mean neutral; of course nothing is or can be perfectly neutral. I mean it seems no one is even attempting to be neutral or even attempting to portray themselves as neutral. There is no concept of an anti-agenda agenda.
Wikipedia!
It's quoted in the GitHub link, and presumably it'd be trivial to find in the list archives.
This isn't as benign as you characterize it, since it's basically "this date handling bug must have been created by a woman since women lie about their age". Lazy misogyny is still misogyny.
> Is it professional to make such a joke on a ruby mailing list?
I understand what you're doing here (https://rationalwiki.org/wiki/Just_asking_questions) and so aren't looking for a real answer, but the actual answer is: Of course it's unprofessional. Make "women jokes" while working at any modern company and see what happens.
> Is this reaction proportional to the original joke?
Again, this is a mischaracterization. This comment wasn't the cause of the change, but a final straw.