With so many places up for grabs it was easier for teams to qualify, and the headlines often focused more on the countries that failed to reach the tournament, he added.
Ghana, one of 10 African sides at the World Cup, advanced to the round of 32 on Saturday despite finishing third in Group L after their 2-1 loss to Croatia.
"With so many teams qualifying for the World Cup, I think the value of the competition in terms of being rare to be in the World Cup, is, in my opinion, still debatable," he told a news conference when asked if the number of berths for African sides was justified.
"Even the qualification matches in Europe and Africa, they start to lose significance, meaning, because everybody is qualified."
The World Cup should be structured in a way that ensured the qualification process was serious, tough and competitive and organisers should also consider that players had endured long seasons, added Queiroz, who is making his fifth World Cup appearance as a coach.
"So it is a lot of small details that demand in the future (that they) should be studied very, very carefully, of course."
Discussing his team's defeat, the Portuguese coach said they made costly defensive mistakes against Croatia and would learn from those ahead of their round-of-32 match against Colombia in Kansas City on Friday.
"The best thing of this game, it is what we learned from the game. We learn a lot of things in terms of our evolution, our progress," he said.
"We have a clear picture about the performance of some players, what we can do different in the next coming games."