"local maxima"? The commenter never said that progress was finished, and that nothing more should or could be done. He was merely describing it as better than the prior state, from a utilitarian perspective.

Relative to standards of living in America today, the situation described in the article is abhorrent. But social/cultural progress is not fast, direct, pretty, or easy. America struggled through many stages of oppressive, inhumane periods. Even today's society may be described by future generations as barbaric (e.g. wage slavery, government surveillance, etc etc).