Its optimistic in a really odd way tho - we see a society that's gone from what was basically a commune under Rick to a capitalist society with money, private property, and presumably taxes to pay for railroad and a world where you get preferential treatment from law if you know right people. That could have been presented as humanity slipping back into pre apocalyptic status quo but instead was seen as a sign of hope even when at certain points in story (esp. with Michonne) that pre apocalyptic world was a time when people never truly lived.
It was a woolly fluffed ending for me. A big point could have been made but was avoided