I may be speaking out of turn for kinnem, but I expect it was more about the 2.5 cgpa for AF/NROTC. Both programs have a make or break year, it is just different.
For AFROTC as a sophomore you must be selected for summer field training. The avg cgpa is 3.0/3.1 for tech and 3.3/3.4 to be selected. Way higher than the author assumes is true. Not selected for SFT and they will disenroll you. The board is masked in regards to which cadet is on scholarship and which is not.
~ Hence why many call it a 2+2 scholarship. Only really guaranteed for 2 years.
NROTC has that break year too, but if I am correct if you are on scholarship it is guaranteed for 4 years.
Additionally, for AFROTC and NROTC at least 80% of all scholarships go to STEM majors. AROTC/NROTC MO does not place that emphasis, thus why he felt they were not AF or Navy.
Finally, I know for AF to make rank you will need a Master. I don't know if it is still masked at O4, but many O3s will have their Master degree by the time they make O4 because if they want in residence (ACSC/CGSC) than they want that in their packet for selection. I know it is not masked for O5. IOWS, I think for every branch it is common to have a Master degree when you are an O4.
I don't think he was meaning a slight at all. I think it was the assumption a 2.5 cgpa in underwater basket weaving would equate to a commissioning in the AF or Navy from a ROTC perspective.