We still have lots of great examples of sportsmanship in golf, like the guy who DQ'ed himself from Q school a few weeks back.
As to Nicklaus, while I agree he would never cheat, years ago at CP during the Crosby, they were playing lift and clean, and he spent a good five minutes getting the best possible lie out of his placement on 17 FW. I recall being embarrassed, but also educated to know these guys take full advantage of the rules, and take them to the limit for their own benefit, while not exceeding them.
There were examples, like Arnie smashing his club in the sand at the Masters, up to Tiger allowing the crowd to move a boulder in a waste area for his shot, of a tinge of "stars getting the beneifts of the rules decisions." then and now.
There are always examples (more and more) of TV viewers catching infractions, like Watson getting a 2 stroke penalty years ago, but still winning by 3, etc.
All is well in golf, in my humble opinion. The rules infractions seem to be random and enforced. If anything, TV makes them even more honest. What doesn't get caught on tape these days?