John Stuart Mill was known as a Utilitarian. Also he was knows as an "Empiricist" and a libertarian. His philosophy in economics was akin to the great Adam Smith. He is quoted:
"that the sole end for which mankind are warranted, individually or collectively, in interfering with the liberty of action of any of their number, is self-protection;"
He did not believe in Hegelian or Marxist determinism. There is much to be admired in his philosophy.
You are correct that Mill deserves admiration, or at least a helthy level of respect. But I believe Earley is right that there are many people who've mistaken the Founders for proto-Mills.