Well you got half the problem right. It might have been ok with an immutable (argurable) monetary policy if bitcoin didnt exist but you're in a competitive landscape. Your value is being debased by the emission so you'll end up poorer than just saving in bitcoin. Again if CPU power weren't already centralized your argument isn't wrong. The alternative uses changes the economic incentives of mining. So other uses has already centralized it. Governmental attacks are easier for attacking general computing systems because they already control so much of it. I