Because having a revolver or a rifle or something is going to really do anything if the government comes after you personally.
Any actual resistance movement capable of achieving much is going to find a way to arm itself regardless of if the country theyre from allowed guns during peacetime or not, they seem to in other countries that such things have formed in after all. Could be through illicit purchases from elsewhere, or homemade weapons, or theft, or whatever else, it always seems to happen.
“Not slaughtering the Jews” does not require letting Isreal slaughter the Palestinians instead.