Why isn't it socially acceptable for men to carry a bag?  Men have stuff to bring with them too, don't they?

When I was serving overseas in Malaysia with the RAAF

We, serving members had what we called a Mum

A canvas bag with a strap that went over the Sholder used to carry Lunch water a Book or Magazine and waterproof 

real men carry Bags and some real men dont carry bags who cares what a man carries

I'm glad I stuck with my attache case when that stupid belly-pack thing came and died.  If you aren't the attache case type, there's no law that sez what you carry in a lunchbox or brown paper bag !!

yeah i carry lots of stuff in my pants thats why theyre so big

It IS socially acceptable excepting among guys who are obsessed with gender role, obsessed with NOT being thought to be "sissy" or "gay." 

don't depend on them. I carry this bag when i travel. 

Men have wallets and pockets.
Guess you haven't noticed how womens clothing rarely have bulky pockets yet.

It's more socially acceptable nowadays.  Most men seem to carry Back packs/rucksacks/crossbody courier bags and a few braver souls wear over the shoulder or cross body man bags!

get a briefcase then.

Real men who want to carry a bag just carry a bag. They don't give a stuff for whether it's "socially acceptable" or not. They know that people who care about whether it's "socially acceptable" are sad bozos who wouldn't know how to get a life if one smacked them in the face.

REAL men only carry a wallet and a multitool

Let’s face it, man bags look gay and fanny packs look like you are digesting a small animal. 🦔 

Yea we do, it's called a fanny pack but now very uncool to wear.  I used to carry my gun it it, my wallet and other stuff I needed .  It sucks when useful stuff goes out of style

Few men may not like it but actually it is acceptable by mass people.

Plenty of guys has a cross body messenger bag. Or get a smaller back pack. 

It is 😂 who told you it wasn’t 

Its ok in my country, state for a guy to have a backpack.

carry a back pack

I think this is changing rapidly, esp since plastic carrier bags are being phased out.  I used to just see young guys with rucksacks and middle aged men with attaché cases.  Now I see men of all ages with rucksacks and messenger bags in all styles from casual to formal, not to mention pulling re-usable shopping bags from a pocket.  I'm seeing more and more guys with tactical thigh packs too as a sort of many handbags.  I'm not sure that it will last as a fashion but they look really practical.

There are more and  more places carrying bags suitable for men. The mall Chain Aldo has dozens of men's bags. Here's their men's bags section. https://www.aldoshoes.com/ca/en/men/bags-accessories/bags-wallets 

A quick search of men's bags gives hundreds of masculine options that even a tough guy like Danny Trejo could carry. Nevertheless if what you want to carry is pink and sparkling  and has Tinkerbell on it then it's not the bag itself that's the problem. 

I am assuming that you are referring to a handbag. I think it's socially  not accepted  for a couple of reasons. #1. it takes away from a man looking manly. #2. I don't want my man, mate, boy friend, competing with me as far as who's wearing the best looking bag. #3. It's always been a woman's thing for very good reasons. #4. IT'S JUST NOT NATURAL.

Men have choices.  Different things can be used in place of a purse.  I used a metal clip board with a storage box attached.

Trans guys do, most men don't need one.

@anon- fanny packs have never been in style. 

That's what briefcases and backpacks are for. That's what most men I know carry.

I see a lot of men carrying messenger bags, too.  In a large urban environment, it's not socially unacceptable to do that.

They do now, it's called a murse. Hold on honey, I have to check my murse.

Where I live, it is 100% acceptable...where do you live, what kind of place says men can't have a bag?? 

It isn't.  Why do you think it is?

Becasue it's gaaye liek Marvin

Men have pockets 

A wallet and keys are all I ever need to carry.