That whole senna hearing the traction control story is such rubbish, I dont think anybody but the very simple believe that crap. And the word 'illegal' is used a bit liberally in formula 1. Flexi wings are 'illegal' but here we are. Renault mass damper suddenly became 'illegal' after 18 months of scrutineering and FIA approval. The FIA finding something new on F1 cars and then banning them doesnt always make it illegal in the first place.
And the example of Michelin equiped cars dominating is yet another example of 'the package' being far more important than the guy driving it. Ferrari had the choice of switching much like anybody else. They chose not to, and it cost them badly. Bridgestone were basically designing a tyre to suit ferraris needs and to hell with what the rest wanted. Ferrari as a result had no chance of being able to out-test Renault, Mclaren, Willams etc throughout the season. The sheer amount of feedback for future development that Michelin was able to amass crushed bridgestone.
Once again, the overdeveloped tyre was the dominant one. The only thing that brought Ferrari/bridgestone back was a joint cry that the michelin's were flexing in such a way under high speed loading that they were receiving an unfair advantage, and the FIA magically agreed.
Ferraris win streak wasnt 'only' about money and testing, but i think that it played a much more significant role than either of the drivers would ever play