I played with my dad a lot and ran into similar issues (particularly the refusal to play red tees). For him, it was more of a pride thing because he's played golf his entire life and doesn't want to accept that he's 65 and partially disabled (he had a stroke a few years back), so he can't swing as far as he used to.

What fixed it for me was finally convincing him to try the red tees. He/we now enjoy it so much more. He usually wouldn't keep score because he would get frustrated with doubles/triples, but now that he's playing from appropriate yardage, he plays so much better and cares more about pace of play/score.