If they raise inflation rates to attack BTC it would have an impact on the economy too, and they would have to explain people about it. But yeah it's a problem, governments could spend billions in propaganda and promote their forks as well bribing everyone up, so it's not only a potential 51% government funded mining operation attack, but malicious hard forks too (I suspect all of these bigger block hardforks are promoted by certain governments)
I remember this topic had already been discussed in the past
In fact, the money to be printed won't necessarily raise the inflation rates. The US government ran two (or even three) rounds of quantitative easing with inflation still being exceptionally low. How come? Because the newly printed money never entered the real economy. It was used mostly to extinguish the bad debts that came about from subprime loans which caused the subprime mortgage crisis in the US in 2008. The money itself was sterilized by financial and stock markets, so the inflation was kept on a tight rein and at its lowest levels. Basically the same would happen to money printed to kill or destroy some coin (if it ever came to that)