The most basic program (least prestigious, minimal prerequisites) indeed extends over just 6 months. But those are dense and intensive 6 months, that in terms of academic-hours worth over 80% of 3 years of college (~1400 hours vs. ~1700 hours). Soldiers in this program are required to serve 6 years, exactly because this training is hardly enough, and in practice it takes another 1-2 years of OJT and further courses before they become reasonably qualified.

First part of your response is qed.

I thought we were talking about entry-barriers and qualification requirements.

Precisely. The current discussion opened by comparing veterinary to programming. The former requires 7 years plus to qualify, the latter, as you've aptly pointed out, can be accomplished with several months of training.