Unless you understand that "theory" entails conjecture you are not working with the correct definition of theory. Do you see the words "system of assumptions" in the American Heritage Dictionary definition of "theory", or does cognative dissonance kick in whenever those words come up?
I suggest you either learn to accept the consensus meanings of English words, or choose another language in which to converse. No part in the definition of 'theory' involves an inference from incomplete data, or guesswork. And the first sign of a charlatan is an attempt to change the accepted meaning of terms.