Wayne, yes you are right and youngsters like Spieth will undoubtedly earn a spot in future years...though I would like to see a team format introduced to the Olympic tournament, with (say) the top 8 countries sending four-man (and woman) teams, with perhaps the 4th player being a captain's pick.
And yes you are right about the Ryder Cup and President's Cup etc. asking a lot of the players - the golfing calendar is packed and it's tougher for the players to fit the Olympics into their calendars than it is for the tennis players for instance.
Having said all that, I think you'll see some pretty emotional medalists in a few hours' time and I suspect Jason, Rory, Jordan et. al. will be doing a little soul-searching...I loved Garcia's comment last night ("Whoever said @OlympicGolf didn't mean anything must've been on drugs cause this is absolutely amazing!!Coming to Rio, my best decision ever!")
I should add that I'm being somewhat hypocritical, as I am currently discouraging my 25-year old daughter from attending a wedding in the rain forest of Puerto Rico this coming January due to the zika scare there! (the betrothed are thinking hard about shifting the venue back north given the concerns of many)