In 2022, one cannot go back to the 2010s and repair whatever bad business decisions have been made. So the FTC decisions must then be seen in this light. Therefore, the case made by this article is made in the context that a dominant player in an industry has made decisions that slowly but surely doom them and seeing the imminent doom, they have found an acquirer who might be able to rescue them.
The FTC is operating in a universe conditional on iRobot already having done what they've done. Consequently, even if you can blame iRobot for getting into the situation, you must also blame the FTC for closing off their escape route and de-facto enforcing the sell-off to the Chinese.
As for the other thing about neither the FTC nor the EU actually bringing any proceedings against Amazon or iRobot and simply requesting information: this seems either naïve or a misrepresentation of how governments act to end deals. It's not that convincing to me that organizations that have expressly indicated that they want to break up the big companies are "just asking for information".
One thing I find interesting about Western governments is that they're very similar to the Indian governments that I am familiar with. They employ the same tactics. Every immigrant knows to be rightfully fearful of the white, pink, blue, and yellow slips and the RFE notices they receive. A simple "Request For Evidence". A common strategy back home in India, too.
I suppose the reason those in the West are less aware of these things is that the standard bureaucracy mostly works if you're a domestic W-2 employee. Interactions with the government are few and generally functional. So they come to believe that the government is a highly honest machine: if it asks for X, it does not indicate anything more than a request for X. Those interacting with the more politicised parts of Western government find that they strategically employ the usual tactics that Indian bureaucracies wield routinely at the lowest level.
Overall, therefore, I don't find this convincing. Looking at the other things that Matt Stoller writes, I also suspect there is a partisan slant to this.
0: Businesses are hard. You operate in the fog of war. We could easily be telling a different tale if the bet paid off.