The "non-bitcoin portion of my portfolio" is my ability to earn a living via means that would still exist if Bitcoin goes to zero.
As far as savings goes, I'm only interested in forms that are transportable frictionlessly across international borders. Whatever form I keep my savings in, it should be capable of travelling with me no matter where I choose to live.
People have different subjective valuations for financial security. In my opinion it is entirely astute to have 80% of your net worth in bitcoin, for you it might be 100%. Many find even 5% intolerable.
Life brings all kinds of situations where you cannot earn a living and need savings. It is foolhardy to think you are immortal.