"Really not happy with the FIFA exco meeting," the CONCACAF secretary general said on Twitter. "Every'one protects their own interests rather than doing what's right. Convenient decisions."
CONCACAF had wanted four places at the 2014 World Cup but were left with 3.5,the same as in South Africa last year, when FIFA decided not to make any changes to the allocation of slots on Thursday.
A "half place" is a berth in a two-leg play-off with a team from another confederation. The winner qualifies for the World Cup.
Blazer, an American, was angry that Brazil, who qualify automatically as hosts, were not included in South America's 4.5 slots and suggested Africa's five places was also too generous.
"The last time we hosted, in 1986 (Mexico) and 1994 (United States), we didn't get an extra slot. Why should South America?" he said.
"In 2010, Africa had six and only Ghana advanced (beyond the group stage). Why do they have five and we 3.5?"
"We are 35 members who are very serious about qualifying. We want to be treated fairly and given enough opportunity to be successful. Hear us."
Africa had an extra team last year because South Africa qualified automatically as hosts.
CONCACAF had three teams at the 2010 World Cup with United States and Mexico losing in the last 16 and Honduras going out in the group stage without scoring a goal.
They lost their half place when Costa Rica were beaten by Uruguay in a two-leg play-off.
Blazer added that Oceania deserved more than half a place.
"I think they should have a whole place. It was a big error in 2003 to strip them of it. They should get their missing half."
Oceania were awarded a whole place in 2003 but FIFA then back-tracked and ruled that they should play off against a South American team.
