The investors paid for the full probabilistic model, where in 10% of the cases Cuil would have succeeded in beating Google and would have made tens of billions of dollars. That alone is worth 10% * tens of billions = billions. 33M for that doesn't seem much in that perspective.
Your statement about "I am certainly sure" and "10 times more" ignores the probability distribution of your potential success, and how big is your success in each one of the cases.
I am sure not everyone would agree to subscribe to this rule, but I do.
By all means it should not take you $33M to recognize that you are in the wrong direction, the first 2-3 should do the job, unless you choose not to see what is happening in front of your eyes.
This is to be said to the founders and investors altogether.
Cuil was a joke, an expensive joke, period.