The 1 and the 0 are arbitrary.It is far more correct to say on and off for primitive computers or logic-high and logic-low for modern computers that use two-state logic. Three-state logic is also used, with the third state not actually being a logic level but an uncontrolled condition. Two and three-state logic systems are used because they are simple and easy, not because they are the way the world works. The world and the people in it are far more analog.
Why aren't concrete metaphors and analogies for spiritual things more precise? Why must we use metaphors and analogies to explain spiritual matters? Why are they so dang subjective? Why is spiritual wisdom so inconsistent between cultures, between individuals?
I love that word 'arbitrary'. Truth can be seen as arbitrary and yet if truth is actually concrete.
Indeed why aren't they as spiritual analogies and metaphors more precise? Because the receivers of them are not precise.
Why must we use analogies for spiritual matters? Ask O'Sensei, he pointed it out quite concretely. Physical matters science has a good handle on but spiritual it has hardly even started.
Subjective depends on what you call subjective. For those not used to seeing a reality it is subjective.
Why is spiritual wisdom so inconsistent between cultures and individuals? Is it? For those without it then it would seem so. For those with it then they see the similarities and consistencies.
Zen specialized in such analogies but actually were mainly designed for the one person the koan was given to based on the zen masters spiritual perception of what the particular student needed to contemplate and get to grips with. Quite an ability I would say, especially when it's purpose was by that one thing to lead the student to enlightenment.
So I say to you that I find the words of O'Sensei far from spiritual ramblings and the job for Aikidoka is to one day see the concreteness of them.