The problem with reality for rational understanding is that it is hidden between being either “either or” an orthogonal contradiction (like “particle” and “wave”) or the opposite “both and” this contradiction, since it can’t be neither “either” nor “both and” at the same time.
According to rational understanding, reality thus instead simply can’t be. This understanding at first appears totally stupid, but at a second thought, it is actually consistent with the empirical fact that reality is ever-changing (by being what one would expect rationally from something that is although it can’t be). The understanding thus paints a picture of a reality that exists only in terms of change.
Such picture (model) of reality is not problematical for science in itself (see modern mathematics and quantum mechanics), but it is problematical for the marketing of rationality (ie, science) in competition with all kinds of beliefs to a public whereof a majority lack ability to understand the picture (model). The picture (model), and together with it, rational thinking, thus runs the risk of being discarded in democratic elections.
The problem with reality for rational understanding is thus that rational people may discard both rationality and the results of it democratically by being inable to understand it. Rationality is simply voted to the sink.