A couple of points.
First, our "rationality" is not as great as is often touted, and so we aren't as rational as many would like to believe.
But more to the point, because of the structure of rational thought (linguistic, propositionally based), we are able to double check the results of rational analysis with methods that yield (relatively) deterministic and predictable results. In
some measure, we are able to double check the results of rational cognition, and this is of enormous utility in terms both of excluding bad results, as well as making building on one rational result with another rational result reliable.
I personally don't consider myself particularly rational; my training is in mathematics, and it's my impression that my intuition is my strength. But these are simply multiple tools in the cognitive tool box, and it sounds like you're suggesting we should avoid being rational, or focus on use of a different cognitive tool, preferentially. While I wouldn't suggest avoiding using non-rational methods where appropriate, one needs to bear in mind the strengths and limitations of any cognitive tool one uses. [*see below] (In particular, irrational behaviors in the heart of rationality, in the form of cognitive bias or other errors, can lead people to mistakenly place too much confidence in a rational result. But that's a side matter beyond the general strengths and utility of rationality proper.)
(I recently watched a video which suggested that our dependance on the cognitive personality of one hemisphere of the brain, that hemisphere accessible to the language centers, may have skewed our development as a species or culture. I don't offhand know what to make of that. I'll post the video below.)
http://www.youtube.com/watch?feature=pla...Fs9WO2B8uI
[*note] I would argue that the system of promoting certain employees to positions of greater responsibility is a systematic method for evaluating people on their ability to use multiple methods of analysis and strategies, and the learning gained through experience, in solving problems relevant to the running of the specific business. It's a system which operates (loosely) on the principle that the best predictor of future performance is past behavior. Consistent with that principle, people are promoted on the conclusion that, regardless of how they arrive at their decisions, the combined set of cognitive tools they employ will outperform those of the person who was passed over for promotion. Intuition based on professional experience is a bedrock tool in our society, and its not really a typically "rational" cognitive process (though lesser or greater amounts of reasoning may be involved).