What's the point of this article? That the rating agencies have a lot of power? What is his proposal? He has none. Attacking the ratings agencies allows governments to distract the public from the real issue, which is that government finances are shoddy in most western nations. He is furthering this charade, deceiving his audience.
What would happen if there were no ratings agencies or if their ability to analyze investments and provide recommendations were curbed? Investors would have less insight into the government's finances and would therefore be less likely to loan them money, or would require greater interest rates to compensate for the added risk. Governments, therefore, actually benefit from the ratings agencies, especially when their finances are actually in order. Think about it, if the ratings agencies were shut down today, investors would be left to their own devices when evaluating government debt, which is quite a task given the complexity of government finances. Many would just assume to avoid it, which of course would send government borrowing costs skyrocketing.
When you buy stock in a company, do you just blindly throw money at a ticker symbol? Of course not. You might take a look at their financial statements, which have been verified by a third party. Furthermore, you might do additional research on the company. You would probably also look at the analyses and recommendations of other researchers. This provides an incentive for the company to keep its finances in order, because otherwise there are a lot of people who will call them out on it. Why would you loan a government money without doing the same?
If governments don't want people evaluating their debt, then there's a simple solution: don't issue debt.