How far back can a consoler player play the older golf games.
If you disregard Multiplayer/online aspects, a long ways back.
My PS3 has full TW14 with all DLC and it works and plays as if it were brand new today and will continue to do so essentially as long as my PS3 lasts and/or Sony allows re-downloading of PS3 content (if I were to need another PS3 at some point).
PS2 era games all work just fine too, and honestly once you are back that far, as long as you have the hardware & disc/cart, it all continues to work with no issue.
Whether it's PC or Console, Multiplayer/online stuff will be the sticking point moving forward unless someone offers direct IP connections again in a golf game. Otherwise there will be ongoing costs to providing multiplayer access for the developers, thus necessitating an ongoing business model.