The governments, all of them, don't give a shit whether those ex-teenagers have to live a life that is emotionally-scarred and physically handicapped. (Assuming they manage to get through the military experience alive, that is.)
I have met guys that went through a year or two of war then went though decades and decades of ruined life, as alcoholics and post-traumatic sufferers and divorcees. All jokes aside, maybe it would have been better for them to have died while 'on the job'.
So, Yes. It is immoral to groom teenagers into signing up for the Army, Navy, or Air Force.
I ask because the word has a long history of being used like this:
"Born in Lisbon, Luís was educated in the Cortes, groomed for a career in the military." - https://en.wikipedia.org/wiki/Lu%C3%ADs_Manuel_da_C%C3%A2mar...
"Born to an upper-class family, Zhou was groomed for politics" - https://en.wikipedia.org/wiki/Chifeng_sui
"Though he was being groomed for a place in New York's legal establishment ..." - https://en.wikipedia.org/wiki/Albert_DeSilver
"Scholars are groomed for the highest levels of command and management in the Singapore Armed Forces (SAF) and beyond." - https://en.wikipedia.org/wiki/Singapore_Armed_Forces_Oversea...
"As a younger son, he was groomed for a career in the church from an early age." - https://en.wikipedia.org/wiki/Melchior_Zobel_von_Giebelstadt
On the other hand, if you think "groom" is always negative, then of course it's immoral.
Do recruiters stretch the truth and even lie? Yes. Do they use high-pressure sales techniques on teens? Yes.
"12 Military Recruiter Lies" - https://www.operationmilitarykids.org/12-military-recruiter-...
"Tracking military recruiter abuse / For one year, we documented reports of abuse, harassment, and misconduct by military recruiters. Here's what we found out and how we can stop it." - https://afsc.org/news/tracking-military-recruiter-abuse
As the latter points out, "a year of operating the Military Recruiter Abuse Hotline has shown us that it is all too common for young people to face harassment, lies, and other misconduct as they interact with recruiting stations. "
Yes, that is abuse and immoral.