how many different aspects of government are keyed to inflation? wages, budgeting, taxation, trade policies, monetary policies, entitlements…
if your entitlements are going up due to inflation, you’re ok with that. but how would you feel if your entitlements were going down due to decreased inflation (or deflation)?
so, you save money by not increasing budgets according to real inflation and you save political capital by not having to either cut budgets or increase taxes during deflationary periods. badda bing badda boom, kill two birds with one stone.