Anyone can be a serviceman. (I say that as a father of a soon to be Navy Spec. Ops recruit). They get a spexialized education, money, medical and retirement. Not everyone can be a D-1 athlete. Give the players the equivalent, less the retirement.
Not everyone can serve. Many cannot. Most refuse. Most kids refuse to put forth the effort to be a D1 athlete in any sport. Very few are good enough for the highly specialized training jobs!
Military training is not equal to a four year degree, generally it is quite short of a degree. This is how the military saves money. Additionally, they usually double up the course load to save more money while demanding many more hours of military duty while attending training, often the total hours per week are in excess of 100 hours.
Sure, the military has medical coverage while they are in the military. They do not get coverage after leaving unless they do 20 or more years, same with retirement. The exception is for injuries incurred on active duty, but this is akin to Workers Compensation, which everyone gets if injured on the job. Student athletes get world class medical coverage and treatment that military members can only dream of. Vets cannot even dream of military coverage (Try treating with the VA and see if it is anything close to a student athlete!).
Military members are happy to serve. Many would have been happy to be offered a four year full ride at a good university. If you were to equate the demands and requirements placed on these young kids in the military against the demands and requirements of a D1 athlete, you would probably offer a D1 Athlete a 1/4 scholarship and let's not pretend that any college athlete has lives of the their buddies, unit, innocents, and the world riding on their performance. If military kids screw up, it can mean others die and he could die or go to jail for the rest of his life. If a kid fumbles, at worst he gets benched for a while.
Your argument is that D1 athletes should get paid extra simply because they are good at a sport. Sorry, does not equate, they should be thankful that they can get a free ride to a university. They have the opportunity to prove themselves to the pros. Both of which are far more than the average kid will ever get.