In my opinion, the essential reason Macdonald did less architecture than most of us suppose and why he may've tired of it a lot faster than we realize (other than his constant decades long work on his own course---NGLA) is because the guy was always one of those "amateur/sportsmen" designers. In other words, he never got paid because he didn't want to be and he didn't believe in that. He said so himself in his 1926 book.
To get him involved in a project it looks like you had to give him a ton of control and that's why they could only lure him to do Lido by telling him he could do anything he wanted to. Also probably why The Creek Club made him the president of the Kellenworth Corporation that owned the land and now a recently discovered old article mentions that Macdonald was the Chairman of the committee charged with creating Piping Rock golf course, Macdonald's second project in 1913.
On the other hand, it has always just astounded me that Macdonald was never made the president of the USGA or never even got on the so-called "Latter" of the USGA. It just seems like if anyone over here was destined to be that it was Macdonald. I think there were some dynamics going on in that organization for about its first twenty plus years in which he was closely involved with that organization that we just don't know about. I hope someday someone can figure that out and what was going on.
Something tells me even though Macdonald surely was a domineering guy in all kinds of ways that he was also remarkably clever perhaps in some mode of self-survival. In other words, it seems like he had a pretty refined sense of when to hold 'em and when to fold 'em. I think what he came to realize is that even though he was generally perceived by some or even many as the sort of "go to" guy over here that there were just some he realized he could never dominate or cross and so at some point in the late teens or early 1920s he just sort of bowed out and went into nearly twenty years of an increasingly reclusive mode. It seems like his attitude was "if you need me you know where to find me but if you do things will be on my terms and not yours."
Some sought him out but mostly the reclusiveness progressively predominated until eventually things got to a point that are probably best represented by that letter he sent to Perry Maxwell who sought him out:
"Young man, good luck to you but I would not walk around the corner for another golf course project."
In the interest of the type of historical perspective and discusion I would like to see on this website, I will now add the caveat that what I said in this post is only my opinion, nothing more! Perhaps tomorrow my opinion will change if someone offers something credible to the contrary!