Yeah, no one in the middle class needs tuition help.
Yes, rolleyes indeed. I'd say kids in the middle class are
more likely to need tuition help. Kids in the lower quintile, assuming their high school performance was strong enough to get accepted into college, should have no problem whatsoever paying for it with the financial aid system that's in place. Most of the people I've known who have trouble paying for college are the middle class kids, whose parents often make too much and thus qualify them for much less in financial aid but who did not save enough to offset this. Basically the financial aid system assumes that your parents will help you pay for school, which unfortunately is not as often the case nowadays.
No, kids in the lower quintile may take advantage of the college money someday but they're more likely joining (assuming they're joining for financial reasons) for the signing bonus as well as the guaranteed place to live and food to eat for the next few years.
Even granting your ideas about the Army's combat arms (which I do not subscribe to), the combat arms are a decreasing percentage of the total. The military also includes the Navy and Air Force, both of which have increasing levels of technical sophistication.
One might suggest that this is part of the problem we've had for the last few years. Too much emphasis on whiz-bang toys for the Navy and Air Force, and not enough Joes with rifles to put on the ground where we need them.
Of course, none of this is relevant to the OP anyway since it's not as if low socioeconomic status is actually indicative of low intelligence. It can be indicative of a poor education in many cases, but part of my point is that the military is more than willing to train you for whatever they want you to do, whether it's carrying a rifle, driving a tank, tearing apart a radio, or messing with whatever those big complicated looking pieces of electronics are that they show in the commercials. So it's aptitude, not education, that matters.
And there are still plenty of jobs, from cooks to combat arms, where the only aptitude really necessary would be following orders and teamwork...neither of which require much intelligence.
But yeah, back to the OP...fails off the bat because it seems to make the assumption that only lower-class kids are choosing to join the military for financial reasons. Which is entirely untrue. It also assumes that a majority join for financial reasons...also untrue.