Because it lands on irrational grounds the quantum theory doesn’t make sense. The results of the mathematically rational theory are "irrational". The theory for instance cannot predict through which one of two slots a particle will travel.
Now the question is: Is the irrationality of the theoretical results due to the nature of Nature or due to an unsuspected fault within our human interpretation of Nature?
Reality has to make sense.
In short physics' "faultless" theory, in the eyes of this writer, doesn't match "reality"!
Amazingly there is a solution to this dilemma!
This writer discovered an arbitrary assumption at the very base of physics' theory!
That arbitrary assumption, being "assumed" or "taken for granted" before any equation of physics is even considered, should it be chosen wrongly, would not in any way jeopardize the validity of physics' mathematics!
Now physics "fautless" mathematical edifice is resting on "shaky" grounds though!
And an alternate interpretation of Nature, that mathematicians-physicists have nevertheless no reasons to fear, has been elaborated; this writer offers an alternate to physics called the gravimotion mechanism or theory.
In the eyes of this writer, there is another split, now specifically between Nature and the quantum theory, that mandates an alternate.
This divorce is exposed on line at Entropy and the Quantum Theory