It's defamation because they know their information is frequently incorrect, that it is trivial for people to get outright fraudulent transactions attached to people's "credit report". Knowing that, they then present that information as fact to others, despite knowing that the information they provided is used specifically for purposes where false information will add significant costs to the people they're reporting on.
Now you're right, I can get credit monitoring, in which I pay money so that I can spend my time verifying they're not publishing fraudulent information. So now it goes from defamation to extortion: we'll defame you unless you pay us and do the work of ensuring we don't defame you.
They do not publish fraudulent data. They publish data provided by the credit grantors. If the credit grantors don't do their due diligence, that's on them, not the CRA. And if credit grantors fail to due that due diligence often enough, they get kicked out.
It's defamation because they know their information is frequently incorrect, that it is trivial for people to get outright fraudulent transactions attached to people's "credit report". Knowing that, they then present that information as fact to others, despite knowing that the information they provided is used specifically for purposes where false information will add significant costs to the people they're reporting on.
Now you're right, I can get credit monitoring, in which I pay money so that I can spend my time verifying they're not publishing fraudulent information. So now it goes from defamation to extortion: we'll defame you unless you pay us and do the work of ensuring we don't defame you.