as a principle I think it's pretty shady to lock away part of a game people payed for behind a paywall
things could be "fairer" if games atleast came with a 1-2 month ps+/xbl gold pass, so that you "only" need to buy a game a month/all 2 month to have online multiplayer for the full year
that said, personally I'm a big fan of the "instant game collection" feature of the PS+ and already have paid till 2015, so ..