There are likely articles written about every legit investment as fraud with some set of numbers to back them up.
If you look hard enough there is "proof" that the usd dollar is a scam, which I think we can all agree is not true.
I doubt regulators can investigate every potential fraud and instead have to be wise where they allocate their limited resources.
This is an unfortunate case of that system not working, but I think that the system works enough that we can be sure 95% of listed companies are not fraudulent.