The 59-year-old Boyd has been appointed as the director of rugby for English club Northampton and takes up his new role at the end of the upcoming Super Rugby season.
Despite dominating world rugby, New Zealand has just five top-tier professional teams, all of which feed into the world champion national side, and Boyd said on Tuesday it was simple mathematics once a coach reached that level.
"Once you get to Super Rugby head coach in New Zealand, there's really nowhere to go," Boyd told reporters.
"I think it's an issue potentially for New Zealand Rugby that there's a lot of experience and intellectual property that ends up going overseas."
That intellectual property is now being used against the three-times world champions, with former Auckland Blues assistant coach Joe Schmidt leading Ireland to number three in the world and their first win over the All Blacks in 2016.
Such is the influence of New Zealand coaches in Ireland in the last 10 years that at one point in the last five years all four of their professional sides were coached by New Zealanders.
Former Canterbury Crusaders assistant Vern Cotter, who spent eight years in France with Clermont Auvergne, also arguably laid the foundations for a turnaround in Scotland's fortunes when he took the role in 2014.
REFEREEING ERROR
The Scots should have qualified for the 2015 Rugby World Cup semi-finals but for a referring error, while last November and now under former flyhalf Gregor Townsend, they came within one pass of beating New Zealand for the first time.
Wales coach Warren Gatland also led the British and Irish Lions to his homeland last year and sealed a series draw, while former Otago Highlanders coach Jamie Joseph is in charge of Japan and Milton Haig leads European dark horses Georgia.
Boyd took over at the Hurricanes in 2015 and led the side to two Super Rugby finals, winning their first title in 2016, and the semi-finals last year.
Despite his success at Super Rugby level, he said he had no immediate plans beyond Northampton and was not looking at the job as a springboard into the international arena.
"I don't really work on goals," said Boyd, who was a technical advisor with Tonga during the 2011 Rugby World Cup.
"If you're in something, you want to do the best you can and if it works out well then another door will open. If it doesn't, then the doors close.
"I didn't really have a goal of coaching international football.
"If you ask me where you think I'll be in three years' time, I actually have no idea."
(Reporting by Greg Stutchbury; Editing by Ken Ferris)
