Erica's response was "because people need a car, but they don't need a gun." This isn't really always the case though. In rural environments, guns are much more necessary. Also, in dense urban environments, law abiding citizens need something to balance out the criminal efforts. No one has the money to pay for enough law enforcement, and there are limits to the number of trustworthy people you could turn into law enforcement.
This got me thinking a lot about licensure for vehicles vs firearms. Air, ground and water vehicles, plus guns all have unlicensed, private, commercial, and advanced license types. Some of these require recurrent medical (and therefore cognitive) testing, and some of these require recurrent skills testing.
One thing is for certain... a 6 round magazine or clip, vs 10 round, vs 20 round, doesn't REALLY make much difference. If you really wanted to shift the bar for unlicensed weapons, it would be single fire vs automatic rechambering. Ie, rolling block, break breach, and bolt action would be the unlicensed category, and revolvers, semiautomatic would be the bottom level of private licensing.
On the flip side, someone who can prove safe storage, handling, and ability with weapons should be able to own a gatling gun if they wanted. Well, actually, they can. Different classification of licensure, but maybe safe storage should be part of the deal.
Also, why not have medical, cognitive, and skills verification for all types of licensing with similar bystander mortality risks? Would it not be beneficial to require in-person renewals every 10 years under 60 and every 5 years over 60? This way, an 85 year old man be less likely to "accidentally" plow through people, nor would someone with uncontrolled blood sugar, or other factors which make them as much of a hazard.
In all of this, how to we reduce the public burden, both to individuals and the government, of issuing licenses and maintaining databases? Should all of these vehicle licenses, firearm licenses, etc be handled by the DPS, or a single, similar agency? Should we combine higher-end license types with Customs IDs, so we can do just one criminal background check, and one DB to maintain?
Anyway, I don't really have a solution to "how to make things more safe without unduly depriving people of their safety nor their pursuit of happiness". Maybe it's not even about making things more safe, rather than making people FEEL more safe.
This is all just thoughts and rambling.
Some interesting documents I came across: