That hasn't been my impression. While they may not be business owners, I think many of the yellow vests could be considered working middle class.
Not by the normal definitions
This is certainly true for the Netherlands (alluded to in the article): the yellow vests (and the supporters of right wing populists in general) are overwhelmingly poor, both in terms of education and in terms of wealth.
Weather or not some rich people are using these people by manipulating them is another question