Seems less dumb than targeting Firefox though. Presumably, in the universe of this conspiracy hypothesis, they would do it in a way that wouldn't effect Edge.
Then they would lose any semblance of plausible deniability, which would expose them to being positively identified as bad actors. What it looks like now is mere incompetence in the face of enormous complexity, which means they lose a lot less face compared to doing what you suggest. Put bluntly, they're hiding within the space covered by Hanlon's razor.
