The poor are used a human shield because if the article had said something like: education is a good with almost-inelastic demand, hence we can raise price

The poor are used a human shield because if the article had said something like: education is a good with almost-inelastic demand, hence we can raise prices arbitrarily and in addition eliminate government support for it :) then they would not have been taken seriously. Wrt "rich", other posts indicate that $70K/yr household income as the upper limit for financial aid in CA. That's hardly "rich".