Or their clients are naive I don’t recognize that they’re being charged more to “decrypt” than the cost of the ransom, or (plausibly) the client is intentionally not paying the ransom because they (incorrectly) believe it means they aren’t giving money to criminals.
We aren't being presented any evidence that they are playing both sides of the table that brazenly. However, I can't see a situation where if the firm were in a position to stop the ransomware globally that they would actually do so.
Maybe an altruistic individual within the company, but not as a directed managerial effort.
The article says there are groups that will do this for you explicitly, and one hopes for lower fees than the companies that claimed they were doing it without paying the ransom.