Most of the time when anyone says it must be nice that they had their college paid for, I tell them the government didn't pay for their school, they gave them a student loan and the repayment was their service obligation. Unlike the school scholarships their kids received which carry no obligation upon graduation. That, they usually understand.
As usual,
@Jcleppe is the voice of reason. His response to the "free education" comment is spot on perfect, although I never used it. If his response was the Yin, then mine was the Yang.
When someone made a comment like that to me, I assumed they knew nothing. I would tell them that xROTC is indeed a great deal, that it's open to anyone and that the scholarships are more accessible than they may think. I told them that ROTC was like a fun/challenging series of extra-curricular activities with excellent summer opportunities--never a word about commitment. If they don't know that much then I might as well try explaining baseball to a Mongolian yak herder.
I've thought about this thread for a while after reading through the comments. Please don't yell at me too much but I have a slightly different perspective on the question the OP asked.
Feel free to yell at me.
I always have downplayed or ignored the "service to the country" sentiment. Not that it isn't a legitimate sentiment, but rather because I didn't believe that was my DS's motivation. There were things he wanted to do and the Army was his ticket. It would have been disingenuous to feed into a jingoistic narrative about military service which is so grossly misunderstood by the 90+% of Americans, who like me, never served. There is nothing wrong with going into an SA or ROTC or an enlistment to prove oneself and asking what's in it for me. That is what post-adolescent kids do. My DS was no exception.
What he learned in 4 years of AROTC and 3 1/2 years of AD was how to use/develop his talents/skills and learn new ones to further the team, which in turn advances the larger mission, which theoretically is in service of the nation. His effectiveness is rewarded. It's a virtuous cycle, borne of his self-interest.
I would take it a step further and suggest that working one's tail off while waiting to be told what to do in service of the "institution" of the military can lead to a very unsatisfying outcome.