Why do so many people in the military have useless degrees?

Because they get degrees from diploma mills that create curricula that match with military training. This allows low quality colleges to market low value degrees to service members who 1) want a degree solely for promotion purposes or 2) are under the misconception that all you need to be successful is a diploma for anything from anywhere. Unfortunately many of these service members come out of college with a degree, but can’t write effectively, or critically think.

Why is a degree considered useless? Never understood that idea. The degree may not be your choice but that's your choice.

There are several issues regarding degrees. First, it should be from an accredited institution. Secondly, the degree should have social redeeming value. For example, a degree in Underwater basket weaving” benefits no one. The individual seeking a degree should determine if the degree sought would better their life, or society.

I completed my Batchelor of Public Administration (Criminal Justice) and My Master of Science (Forensic Science) while I was on active duty E7, in an E9 billet, running a training division in San Diego. Those degrees were directly transferrable to my post-retirement career in Law Enforcement/corporate security.
I'm blessed in retirement to teach Use of Force/Tactical Firearms to Armed Security Personnel and Concealed carry permit holders.

My bachelors degree was in accounting and economics. I was a Signal Officer and after active duty in civilian life, I worked in human resources and after retirement as a cabinet maker and finish carpenter. Did the degree in that field help? Yes! It allowed me to enlist fn 1966 or the Army's "College Option Program". After active that and my military experience opened the door to entry into a higher level position in my civilian career. That particular major also gave me an edge over those who didn't understand the numbers in planning and budgeting.

Why are so many people that were never in the military have useless degrees, but still paying for them 20 years after they graduated???

Online college mills are the biggest scam of the 21st century. My "degree" is my dd214 and I have never not been able to get gainful employment. If hour ego is so weak you have to have alphabet soup after your name then good on you!!

You think they are useless because those things don't interest you. "Online degree mills," is such a negative term. Maybe 10 years ago they were a joke but now even Harvard and Stanford offer online degrees. Earning your degree online is no different than taking a virtual class from a University you physically attend. I earned 2 bachelor's degrees in person, but then decided to earn my Master's online. It was MUCH harder online, they really hold you accountable and there is so much reading to do. Don't knock something just because you don't like it.

Sometimes they push degrees while I'm high demand and by the time you graduate it's more than there are jobs. You can never go wrong with computers and software.

What's wrong with my degree in advance drinking??