Not just that but... as such draconian measures would start of a civil war and even if there was not popular resistance and a voilent, militarized state reaction, prohibition has failed in the US and there's already means for illicit gun smuggling and distribution.
Here's their article on the negative consequences of banning guns
It's also interesting that the "no getting rid of all guns would case problems" is among a list of literal Utopian goals of "What if there were no diseases or no starving people", and the article itself is more an exercise of "Look in order to get X there may be negative consequences to it".
A closer analogy would be if you went "Let's assume all guns magically went poof, would people still be violent?"
Though the comments... not that I recommend reading the comments... seem to run in the style of "Pointing out negative consequences is Privileged!" (Seriously). And specifically to gun control you have folks suddenly turning all gung-ho Drug warrior to justify how gun bans would be okay.
Instead of, you know, going "There may be negative consequences to the goal we want, which means we have to be careful about executing the goals we want."