A handgun is almost totally useless for the purpose of fighting tyrannical troops. Besides, in such a scenario, who the hell cares what the law says about prohibited firearms.
Sure, a backup weapon is handy. I'll give you that. But if and when the time comes to overthrow the government, access to a handgun will literally be the last concern you have.
Compare the importance of the handgun to the revolution with the importance of disarming civilians and cops alike, and it becomes very clear that the handguns for revolution argument just isn't worth it.