Well to be fair the original way of doing it was an accumulation over a year, they simply expanded what they were covering. Not saying I am happy about it.

I am an independent contractor, and I probably spend more than 600$ at Starbucks in a full year.

Maybe it's intended as a subsidy for the Postal Service.

It's intended as a subsidy for accountants and tax lawyers. Congress is the biggest example of regulatory capture anywhere: the lawyers always win.