I enlisted in the USMC in 2007, there were a lot of recruits but the quality was low and they had trouble getting the higher AFQTs joining them as opposed to the Navy or Air Force.
Hmm, that is when I got out - two boot drops, both seemed fine. The infantry is much less likely to draw underachievers though, so we'd be less likely to see the low quality recruits.
The guys going infantry were the best of the platoon by far. With the exception of one or two nobody seemed bad or outright undesirable, just slightly below what I had expected.
It's in the article he linked, sourced from military people quoted.
In 2007? Where are you getting that? For the USMC 01-09 were glory years when it came to enlistment quality, so much so that they tightened requirements - and practically banned recruits and reenlistees with visible tattoos... while doubling in size. I'd be surprised to learn that the Army didn't enjoy the same trend.