What is your definition of "independent economist"?

Claiming that even a majority or plurality of economists overall agree with Piketty, who advocates for some wildly unpopular economic policies and is a literal socialist, is absurd, so your group of "independent economists" must be pretty homogeneous and small.

Independant economist: one tenured by an independent university as opposed to being employed by a lobby group or think tank to promote a specific agenda.

When even Adam Smith supports the regulation of capital, this can be considered a fairly mainstream position.