Why don't officers wear marksmanship badges?

In the Marines, we all wear Marksmanship badges whether officer or enlisted. All Marines must qualify annually with the rifle and wear the badge for the level they shot that year. SNCOs and officers must also qualify with the pistol every year and wear the badge for that level.

Once I was getting a photo for my records and ran into a Colonel who started to chastise me for wearing my Expert Badge. I explained to him that the regulation that governs the wear of badges says all (that means everyone) so I wear my badge proudly. I can imagine some officers being embarrassed by wearing a Marksman Badge, but if I was a Marksman I would still wear it proudly. Everything on your uniform was earned at one point or another and you should have pride in what your earned and the appearance of your uniform.

All should, most don't because they could not hit the barn if they were inside, and aiming....

I served 7 years as an enlisted Soldier and later as an NCO before being commissioned as an Officer. As an enlisted Soldier and NCO, I earned weapons qualification badges in Pistol / Rifle / Grenade and also a Driver's Badge for (wheeled and track) vehicles. When I commissioned as an Officer, I was told by my Battalion Commander not to wear my weapons qualification or driver's badges. He said that all Officers are expected to be proficient tacticians in the weapons and vehicles their troops operate, and as such, enlisted troops should expect that their leaders are proficient without looking to compare their level of proficiency against that of an Officer - which could lead to an Enlisted Soldier or NCO wrongfully comparing their tactical proficiency (if better than the Officer) against an Officer's ability to lead. Now we all know that shooting skills have nothing to do with one's rank - I have witnessed great shooters in all ranks, and as a former Firearms Instructor and Range Master, I have spent days on the range with a few Agents, Enlisted Soldiers and Officers (fairly new to the military or government) in an effort to get them qualified on their weapons. Later, these same troops or agents become Expert shooters and some learned to master several different weapons. I often spent much time on the range with a SFC, a SGM and a CW2 who made me into shooter I am today... those guys could shoot the wings off of flies! Do I think Officers should wear qualification / proficiency badges... for Official Photos (always), and optional for the individual officer to decide, or may be it should be worn by Officers who were once enlisted in order to distinguish between Mustang Officers and those without prior Enlisted service.

Back when I was a 2Lt We did wear marksman ship badges.

I'm not sure of the factual reason why officers dont wear the marksmanship badge, but here is what I was told as a WO1:
Officers are assumed to be experts with their weapon and anything less displayed on their uniform discredits that assumption.

I tend to disagree with any separation in uniform articles. I believe that officers and enlisted should wear uniform articles alike. Another example is the AF (which I’m currently serving). When wearing the service blue uniform, officers are permitted to wear their ribbons but very few do. However, the regulation does not prohibit wearing them. Maybe it is my prior enlisted roots, but I wear that chest candy proudly. It is a sense of pride that I earned my decorations and ribbons.

They train only with pistols and train must less than line soldiers. They are considered last line of defense

Marine Officers wear their shooting medals.

The Maine’s Corps commissioned officer ranks also wear their marksmanship medals. Every Marine is a rifleman first!