Well --
Except that's not what we are talking about here. It's entirely possible to think differently about different subjects, even if you might think those subjects are loosely related.
So one civil right is not as important as another?
Not true. One may still legally possess a gun even if he or she lives with a prohibited person. He or she must merely secure the gun so that the prohibited person doesn't have access -- i. e., in a safe to which the prohibited person doesn't have a key or combination.
That is not all that simple, and it really puts a crimp on the "unprohibited persons" ability to defend one's self and family.
"Arbitrary" is often in the eyes of the beholder.
Setting penalties for crimes is generally within the purview of the various legislatures. They do so within the framework of the legislative process, as part of which interested parties on both sides of the question make their views known. And politicians who support unpopular positions become vulnerable to losing their jobs.
And I have no problem with them being prohibited from possessing guns.
Committing a crime shows a flaw in one's character. One has demonstrated, by committing a crime, a reason to question his integrity, honesty, judgment, impulse control, sense of responsibility and/or trustworthiness. The world is full of people who are subject to the temptations and stresses of living in this world and still don't commit crimes. Serving one's time doesn't magically repair one's character or demonstrate that he has become more responsible or trustworthy than he was before he committed the crime. So I'm not bothered by persons convicted of serious or violent crimes not being able to legally possess guns.
Is that a perfect result? No, but we'll have to wait for Heaven for perfect justice. And overall, I don't see it as necessarily unreasonable that part of the total price tag for a serious or violent crime is loss of gun rights.
Not all felonies or qualifying misdemeanors involve violence or serious crimes. I am reminded of a person who was convicted of a federal felony for building a duck pond, on his property, with the proper local building permits, because some bureaucrat decided that the land was a wetland, and he hadn't gotten the Federal Governments permission.
The reality is that people have been intentionally killed in all sorts of ways, with all sorts of improvised weapons and as the result of all sorts of fortuitous circumstances. That doesn't change the fact that a gun is a particularly effective and efficient tool for the projection of significant force at a distance.
That attribute of a gun makes it a particularly useful tool well adapted to evil applications, such as assuring compliance of a victim, by someone so inclined. Similarly, a gun is a particularly useful tool well adapted to worthwhile purposes, such as defending one's family, by a good person.
Perhaps other tools (clubs, knives, etc.) when chosen by an evil person to further his criminal purposes might also increase his capacity to do evil. So if our legislatures tack on additional punishment for using those tools, I certainly wouldn't complain.
But if the gun is singled out, that's okay with me too. A gun is a particularly effective and efficient tool for delivering force (for good or evil). That's of course why we all prefer guns for our own self defense.