... it's way too often because the responsible people hadn't high enough expectations for quality.
To illustrate, I'll use a years-old case from a German website:
A professional journal had written an article about some websites telling nonsense on their pages, including a quote from aforementioned website. The wrong info was from an article of the website and really not representative, but it was a vulnerability that the journal exploited to diminish competing online sources for info.
What went wrong?
It had been reported that the article included falsehoods, and it was on a list for an update. That, of course, didn't materialize before the journalist visited the page and reported the falsehood publicly.
The people in responsible positions should have taken the defective article down, but their sense expectations for quality were not high enough; they didn't care much, felt instead that just adding the problem to a to-do list would suffice. It was careless; people got misinformed (and the case was not entirely isolated).
In other words; it's not really a good sign if you learn that the problem was known before the shit did hit the fan. It's an indicator for leadership and management failure and lack of understanding of the importance of quality.
Readers are invited to guess which case inspired me to write about this really old issue today...