= Deletionism on Wikipedia
{tag=Deletionism}
https://en.wikipedia.org/wiki/Deletionism_and_inclusionism_in_Wikipedia
Some exmaples by <Ciro Santilli> follow.
Of the tutorial-subjectivity type:
* https://en.wikipedia.org/w/index.php?title=Isomorphism_theorems&oldid=976843241[This edit] perfectly summarizes how Ciro feels about Wikipedia (no particular hate towards that user, he was a teacher at the prestigious <Pierre and Marie Curie University> and https://en.wikipedia.org/wiki/Daniel_Lazard[actually as a wiki page about him]):
\Q[rm a cryptic diagram (not understandable by a professional mathematician, without further explanations]
which removed the only diagram that was actually understandable to non-Mathematicians, which <Ciro Santilli> had created, and received many upvotes at: https://math.stackexchange.com/questions/776039/intuition-behind-normal-subgroups/3732426\#3732426[]. The removal does not generate any notifications to you unless you follow the page which would lead to infinite noise, and is extremely difficult to find out how to contact the other person. The removal justification is even somewhat <ad hominem>: how does he know <Ciro Santilli> is also not a professional Mathematician? :-) Maybe it is obvious because <there is value in tutorials written by beginners>[Ciro explains in a way that is understandable]. Also removal makes no effort to contact original author. Of course, this is caused by the fact that there must also have been a bunch of useless edits not done by Ciro, and there is no <reputation system> to see if you should ignore a person or not immediately, so removal author has no patience anymore. This is what makes it impossible to contribute to Wikipedia: your stuff gets deleted at any time, and you don't know how to appeal it. Ciro is going to regret having written this rant after Daniel replies and shows the diagram is crap. But that would be better than not getting a reply and not learning that the diagram is crap.
* https://en.wikipedia.org/w/index.php?title=Finite_field&type=revision&diff=1044934168&oldid=1044905041 on <finite fields> with edit comment "Obviously: X ≡ α". Discussion at https://en.wikipedia.org/wiki/Talk:Finite_field\#Concrete_simple_worked_out_example Some people simply don't know how to explain things to beginners, or don't think Wikipedia is where it should be done. One simply can't waste time fighting off those people, writing good tutorials is hard enough in itself without that fight.
Notability constraints, which are are way too strict:
* even information about important companies can be disputed. E.g. once <Ciro Santilli> tried to create a page for <PsiQuantum>, a startup with \$650m in funding, and there was a deletion proposal because it did not contain verifiable sources not linked directly to information provided by the company itself: https://en.wikipedia.org/wiki/Wikipedia:Articles_for_deletion/PsiQuantum Although this argument is correct, it is also true about 90% of everything that is on Wikipedia about any company. Where else can you get any information about a <B2B> company? Their clients are not going to say anything. Lawsuits and scandals are kind of the only possible source... In that case, the page was deleted with 2 votes against vs 3 votes for deletion.
\Q[should we delete this extremely likely useful/correct content or not according to this extremely complex system of guidelines"]
is very similar to <Stack Exchange>'s own <Stack Overflow content deletion> issues. <Ain't Nobody Got Time For That>. "Ain't Nobody Got Time for That" actually has a Wiki page: https://en.wikipedia.org/wiki/Ain%27t_Nobody_Got_Time_for_That[]. That's notable. Unlike a \$600M+ company of course.
There are even a Wikis that were created to remove notability constraints: <Wiki without notability requirements>.
For these reasons reason why Ciro basically only contributes images to Wikipedia: because they are either all in or all out, and you can determine which one of them it is. And this allows images to be more attributable, so people can actually see that it was Ciro that created a given amazing image, thus overcoming Wikipedia's lack of <reputation system> a little bit as well.
Wikipedia is perfect for things like biographies, geography, or history, which have a much more defined and subjective expository order. But when it comes to "tutorials of how to actually do stuff", which is what <mathematics> and <physics> are basically about, Wikipedia has a very hard time to go beyond dry definitions which are only useful for people who already half know the stuff. But to learn from zero, newbies need tutorials with intuition and examples.
Bibiography:
* https://gwern.net/inclusionism from <gwern.net>:
\Q[Iron Law of Bureaucracy: the downwards deletionism spiral discourages contribution and is how Wikipedia will die.]