The pressure of performing at big events might be one reason for the deficit.
Walsh suggested another last week: The American habit of peaking too early in a season due to their selection criteria.
"To get to the world champs or Olympic Games, they have to get [in the] top three at their trials [where Crouser produced his 22.65m throw at Sacramento].
"It doesn't matter if they've already reached the qualifying standard or thrown the furthest in the world, if you get fourth, you're not coming.
"So they have to peak for that and then this [world championships] is six weeks later."
What cannot be underestimated is Walsh's capacity to stay composed at the world's top meets.
He first came to prominence on March 7, 2014 in Poland as the first New Zealand male to earn a medal at a world indoor championships.
Walsh won the world indoor championship in March 2016; earned a bronze medal at the Rio Olympics; won a Diamond League meet in September 2015; won the 2016 Diamond League season crown; and extended his New Zealand record to 22.21m last September.
Walsh came within 11cm of a medal at the 2015 world outdoor championships, throwing 21.58m to finish fourth before rectifying that gap in his CV this week.
Walsh's best throw in London was the third-equal longest winning throw in the event's history, behind Werner Gunthor's 1987 record of 22.23m and Reese Hoffa's 22.04m in 2007.
It matched Christian Cantwell's distance en route to gold in 2009.
Walsh's coach Dale Stevenson told Radio Sport that male shot putters struggling at major championships was a recurring theme.
"There's a big but subtle difference between a championship format and Diamond League meets.
"It's much easier to prepare for a Diamond League. They contain smaller fields [of athletes], you're guaranteed six throws, and they [the organisers] look after you.
"Everything is set up for athletes to run fast, jump high and throw well.
"In championships it's more of a brutal test. You can't hide. There's a tough qualifying round and performances are sometimes not what you'd expect compared to the best throws during the year."