I believe proper gun safety teaches people to treat every gun as loaded and safety off. Same reason it's extremely unsafe to point a supposedly empty gun at someone.
Many pistols have safeties and/or hammers that can be easily set to an unsafe when carried like this, if you bump into something or even lean the wrong way.
Theres also the chance of blowing your genitals off or shooting yourself in the hips, upper legs, in a way thats fairly likely to paralyze you or kill you from blood loss from shooting your genitals or femoral artery, if you manage to disengage the safety and also pull the trigger, or draw the weapon improperly in a state of basically threatened panic. Statistically this is rare, but it has happened more than once.
Imagine sitting and then standing and then sitting again with your gun like this.
Ok, now imagine walking or jogging or running and then stopping suddenly. Or even leaning over to reach something.
In addition to being just very uncomfortable with a gun digging into your stomach and crotch, probably the actual main reason this is stupid is that it just is not actually secure, the gun is likely to accidentally fall out and not go off, but scatter across the floor and scare the shit out of everyone nearby.
In ... most (?) of the US, its probably accidentally a crime (brandishing) to even accidentally reveal a concealed weapon without an imminent threat to your person, though this will vary greatly by state, locality and the situation.
Holsters exist to solve this problem.
The closest thing to this that people actually are Appendix Inside Waistband Holsters that clip onto a belt, and go under an overshirt, but over an undershirt, or what are called Belly Bands for non belted people, those are basically underarmor style waistbands with shaped pockets.
In reality these are generally fairly uncomfortable for most people I've ever known that carry a gun on a regular basis.
It's drawn for comedic effect, but ideally it should be in a proper holster (it can still be in that area, like an appendix holster), that covers the trigger and protects the hammer - prevents it from falling out - and also ensures the weapon is always pointing slightly away from the body towards the ground
Fuck me, hold tight. There’s a gun in your trousers. What’s a gun doing in your trousers? What's to stop it from blowing your bits off every time you sit down?
Note that just because Marx said something doesn't mean you should treat it as a gospel.
Marx lived from the early 19th to the late 19th century and didn't witness WW1. Since then, the military has become almost infinitely more powerful compared to Marx's days, where armed workers stood an actual chance against the military. Nowadays though? Not even remotely. Shut off the internet and electicity in a region, ban the press from reporting, send in the military and wipe out any protest, regardless of how many arms there are. Just take a look at Chechnya and how well they've been doing after declaring independence.
The US is an exploitative capitalist country despite having an awful amount of guns.
Northern European countries are significantly less exploitative, while still capitalist, countries without nearly as many guns.
The amount of arms in worker's hands and the severity of capitalism has no relation anymore. Hell, by having so many guns, the US can reasonably argue for ever greater police budgets without much backlash. You wouldn't want children to die in school shootings, would you, you monster?