The surprising thing is that this is actually true! The MAS specifically doesn't regulate unregistered companies, and no scammy company would want to register itself with the MAS - so, like it or not, the MAS has no enforcement power over these scammy companies.
I'm sure the MAS would like to be able to do more than just put these companies on a list, and I think they should be given the powers to shut these scumbags down, but at the moment that all has to be done by the CAD branch of the police... who I'm sure are very good at their jobs, but they're WAY too slow to shut down operations like this. You need to be able to slam the door and freeze the assets before everything disappears to Belize.
On that note: being on the MAS list doesn't mean you are running a scam, but it is very strongly suggestive, because the alert list is a rogue's gallery of ponzis, boiler rooms, pyramid schemes, and outright "run-off-to-Belize-with-your-money" scams.
And also, mate, I'll give you a tip - literally every company I've ever seen that came out with that line, "oh being on the MAS Alert List just means we're not regulated by the MAS, it doesn't mean we're a scam!" has turned out to be a scam. If you don't want people to think you're a scam, don't go around saying "we're not a scam".