Earlier quoted context omitted.
All things you think you know are ultimately founded on axioms, beliefs. Why do you trust sense-data to be real? Brains in vats, holosuites, yada-yada ...
Reality is that which is practical for us to concern ourselves with. When there is an indication that such a notion might be practical knowledge, then I'll give it some consideration.
By that definition reality is completely subjective which rather plays towards my point.
You find the axiomatic basis of scientific understanding to not belong to "practical knowledge". Or that the axiomatic nature of standard logics is not practical? So basically all of physical science, mathematics, logic, ... understanding the epistemological basis of these things is impractical? Because? On such a position theoretical physics would seem to be 'impractical' and not something to concern ourselves [humankind] with - the advances in theoretical physics in the last century or so have worked themselves in to almost all areas of modern 'Western' life.