I think it was right to criticize Mercedes because they are one of the largest team in the sport and they seemed lost for a very long time. The only thing which I did not necessarily agree with him was his opinion that Mercedes as a team were weak aerodynamically and they only won the championships they won because of their power units.
A fair point to make for 2014-2017 but anything beyond that, the gaps between power units were not significant enough to be the deciding factor. And even before, Mercedes was so dominant, the power unit alone could not account for the entire gap they had to the rest of the field, and especially the customers.
It was clear that Mercedes as a whole has been a very strong team, and that includes aero.