There seem to be coherentist and foundationalist schools in epistemological praxis. Coherentism is easy to disprove if you entertain both possibilities. Perception is intrinsically coherentist (and so is intuitive thought). Reason repairs perception, so it should be foundational.
I am naturally inclined to think that it has to do with stupidity but don't let anyone hear it. If you decide to be agnostic, you don't have to compute two full world models. You get to reuse almost everything.