I am as journalist-sympathetic as anyone on here, but even I would agree with the previous commenter's sentiment. Minimization of errors is an old and persistent problem in journalism, and the reasons for this can be relatively innocuous – e.g. general incompetence and complacency; not only in making the error, but also not having a system in place to collect and evaluate feedback/complaints from readers, nor to adequately disseminate a correction if one has been made – to outright dishonesty and cowardice (errors are generally a stain on a journalist's professional career).
The best argument that this is a systemic problem is to simply point out the lack of systemic accountability: as people have pointed out, no major news site has a diff/version history (even though most content management systems have some kind of version tracking), which would be the bare minimum (and best return on value) for digital publishers who prioritize accountability.
(The closest thing is newsdiffs.org, but that's an independent site [0])
If you want a real, recent error that illustrates the low importance of media corrections, I can give you one from this past week: when the New York Times erroneously reported that the Trump administration issued an executive order that would "define Judaism as a nationality". Here's a relevant excerpt from the earliest Internet Archive version of the article [1]:
> Mr. Trump’s order will declare that Judaism may be considered a national origin.
To say that this article caused a violent orgasm of Twitter fury and shock would be a vast understatement; you can search for tweets quote-tweeting the original @nytpolitics tweet to see for yourself. [2].
A few hours later, the NYT article had been significantly updated [3], with no correction or comment by the main NYT social media accounts, or by the individual reporters' Twitters (which are both very active). This is how the aforementioned excerpt was changed (and how it currently is as of today):
> Mr. Trump’s order will have the effect of embracing an argument that Jews are a people or a race with a collective national origin in the Middle East, like Italian Americans or Polish Americans
If the significance of the change isn't self-evident, then this tweet thread+article goes into detail about how big of a clusterfuck the original NYT article was [4].
To my knowledge, the NYT has said nothing about the mistake or the silent correction. Neither have the reporters. And as much outrage as the original article caused, it was all quickly forgotten (even faster than usual) because the mass shooting at the kosher market [5] and the UK elections the next day.
To me, this incident is emblematic of how their accountability is systemically lackadaisical. It's undeniable that the NYT does make corrections, but we only know of the errors that were noticed and were officially corrected. By definition, we can't easily know the errors that were never noticed, or were silently fixed.
In this situation, we have an error that is as egregious and infuriating as one can imagine in today's politics (Trump + executive authority + anti-Semitism + Israel v. Palestine). But also, this is a serious error that ultimately had no consequences, because the original report was attributed to anonymous sources (i.e. no reputation damage) and the error involved matters of abstract policy and political grandstanding.
If the error did cause damage, such as defaming a public official, or causing an angry protest that turned into a riot, then I'm certain the NYT would issue a correction, just as it did recently with its misleading report re: Cenk Uygur and David Duke (albeit after 3 days of complaints from Uygur and his supporters) [6]. But regardless of whether there are aggrieved parties, news organizations should be making corrections solely because they value truth and accountability. That the NYT has so completely and brazenly refused to acknowledge its massive, noticeable fuckup (which, besides the error, indicates a real flaw in sourcing) means that their correction policy should be regarded as arbitrary and unserious.
tl;dr: if they didn't make a correction for an error this big and noticeable, imagine how reluctant they are to issue corrections for errors much less noticeable and/or controversial.
[0] http://newsdiffs.org/
https://www.nytimes.com/2012/07/01/opinion/sunday/article-ch...
[1] https://web.archive.org/web/20191210221006/https://www.nytim...
[2] https://twitter.com/search?q=https%3A%2F%2Ftwitter.com%2Fnyt...
[3] https://web.archive.org/web/20191211010003/https://www.nytim...
[4] https://twitter.com/Yair_Rosenberg/status/120483406506251468...
[5] https://www.washingtonpost.com/nation/2019/12/12/jersey-city...
[6] https://twitter.com/nytpolitics/status/1206722302416687110