If you have a license that "permits" commercial sales in a way that by design makes most business models completely unfeasible... guess what? You'll only get contributions from those with one of the handful of blessed business models. Which will work or not depending on what sorts of businesses models your project is suited for.
Copyleft works fine for things like the kernel that are complementary to tons of different expensive things and nobody cares about otherwise. Permissive works well for Postgres.