Nobody does. And this is the problem with having no inflation. Every economy needs a slight inflation, otherwise people stop consuming, instead save all their money and it gets worse => deflation.
Bitcoin equals gold, nobody uses Bitcoin to consume anything. I don't know which human behavior you refer to.
Your argument is:
"Why would anyone spend any money if it's worth tomorrow?!"
to support a pro-inflation argument
The counterargument / parallel reality in an inflationary world is:
"Why would anyone accept any money if it's worth less tomorrow?!"
The only difference between the two paradigms is that in the later, the currency creators have the power and in the former, the currency owners have the power. It is no coincidence that the financial institution has chosen to be in control of inflation and extract the wealth first, via seignorage, of currency inflation.
yeah it goes counter to all of the anti-deflationary schools of economics, but when have economists ever gotten actual human behavior right?