"I have lived there, they were very persistent, and because of the way they looked after me I decided to accept," Guardiola, who led Barca to a six-trophy haul in 2009, told reporters on Thursday.
The 39-year-old former Spanish international spent two seasons in Qatar near the end of his playing career between 2003 and 2005.
"There is a great passion for football there and it would help them to continue growing as a country," he added.
"If we keep taking the tournament to the same countries we won't live up to the ideals embodied in the name of the competition - the World Cup."
Asked if he would have split loyalties with Spain making a joint bid with Portugal for the 2018 or 2022 finals, Guardiola said: "(In 2018) it looks set to be Europe's turn and everyone hopes it will be Spain, and in 2022 that it will be in Qatar.
"I will help Spain and Portugal but I am sure they will give it to them."
Australia, England, Japan, Mexico, Netherlands/Belgium, Russia, Spain/Portugal and the United States are bidding for the 2018 or 2022 finals.
Indonesia, Qatar and South Korea are bidding for the finals in 2022 only.
