It really isn't like the thing you've mentioned at all. Perhaps a different analogy?
"It will never be necessary to torture for life-saving information, because I have perfect certainty that no information can be obtained that way, so I don't need a moral philosophy that appropriately weighs torture against loss of life."
"It will never be necessary to levy taxes to pay for public goods, because I have perfect certainty that no asteroid will ever head toward the earth, so I don't need a moral philosophy that weights taxation against unprotected asteroid strikes."
> It will never be necessary to levy taxes to pay for asteroid defense, because I have perfect certainty that no asteroid will ever head toward the earth, so I don't need a moral philosophy that weights taxation against unprotected asteroid strikes.
You can't generalize to an argument against all public spending.
It is a similar error to double down so hard on torture never being able to elicit truthful, reliable information.
strenuously? (they're almost opposites)