Let us be clear:
There are a number of things you can point to to criticize “mainstream” news outlets, but retractions and corrections do not demonstrate that an outlet is fake news. In fact, it’s quite the opposite: these self-checks are the central pillar of journalistic integrity.
Journalists, like all other humans, make mistakes. Their job is particularly prone to this by definition, since they often make decisions about whether to publish an article or include a claim based on incomplete information—even a decision that seems correct at the time may in hindsight have been improper. Given their (hopefully uncontroversial) duty to the public to provide transparency, they by necessity will have to sometimes work with less than 100% confidence in their facts. (High-quality outlets will usually alter their tone, which is a closely related but distinct issue.)
In a field where imperfection is inherent even in the gold standard, outlets holding themselves accountable is not only important but crucial to assessing their performance.
Yes, CNN issues retractions. The New York Times and the Wall Street Journal issue retractions. Even Fox News, which has a clear ideological bent, will note when they have gotten claims incorrect.
This does not make these outlets fake news. This makes them real news. You may quibble with the way that they frame that news or the amount of coverage they devote to any individual issue (I certainly do), but if their claims are incorrect, they have proven that they will call themselves on it.
On the other hand, I have failed to find, after significant searching, any instance of Infowars issuing a retraction. Or of CommonDreams issuing a retraction.
This does not make these outlets perfect—quite the opposite. If they cannot be transparent with things they get incorrect, then there is no reason for them to be trusted.
Of course, this is not a dichotomy but a spectrum. I will note that some gray-area sources like BipartisanReport and Breitbart issue occasional retractions, but they tend to either bury the retraction or do it in such a way that leaves the false claim standing. The idea that a retraction is somehow “shameful” and worth hiding bakes in some very backwards assumptions about journalism.
Information abounds in 2017. We have to make quick value judgments about what we trust and do not. Consider the assumptions you’re making when you’re doing so. Are you trying to discount news that is inconvenient to your worldview? Is it because your worldview is objectively correct? Or is it because it’s easier not to confront and challenge yourself?