This is actually a stab at Trotsky, who instigated several reform projects which didn't turn out very well.
At Animal Farm, some committees prove to be more "successful" than others, but they are not necessary. For example, the purpose of the Egg Production Committee is to assure that the chickens lay eggs, but they do that anyway! The Clean Tails League for the cows is of dubious efficiency, and the Wild Comrades' Re-education Committee is an absolute flop. Putting these untamed animals in a "system" does not change their basic nature.
Have a look at the essay posted below. It explains Orwell's own disenchantment with the socialist system.