De Minimus Benefits

From Tuesday's Farm Policy:

" Some states, such as New York, will make a $1 Low Income Home Energy Assistance Program  payment to low-income people in order to automatically qualify them for the maximum federal food stamps Standard Utility Allowance for 12 months.
“According to a source tracking the farm bill talks, the Congressional Budget Office has estimated that raising the minimum energy subsidy states would be required to make to $20 would be enough to disincentivize states from utilizing the loophole, potentially saving the government $8 billion over 10 years.”

We used to have a "de minimus" provision. I'm ashamed to admit I don't remember in what connection, but the idea basically was that something was too small to worry about.  A similar idea applied to certain small claims, whether it was $10 or $25 I forget.   But why shouldn't the government have a blanket policy: no payments, no claims if the amount is less than $20 or whatever?