I think it may be a "city" vs. "small town" south thing.
I'm not from Atlanta, I'm from Houston (an area which is full of greek actives and alumni), so I would consider it a good representation of "competitive southern greek" ideology, not SEC, but Texas greek- UT, SMU and TCU, and getting much more so - Texas A&M.
And, I agree that many kids just don't go greek anymore (and that's from both prominent and not so prominent families). It's just not that big of a deal in the big city.
Like I said before, people are interested, but not so much that they tsk behind someone's back if their kid didn't pledge, or
HORROR
pledged a lower tiered sorority/fraternity. I do think that sometimes people are shocked when someone they thought would have a great recruitment doesn't, and is disappointed with the results, but they certainly don't think the mom's child raising had anything to do with it! It just happens.
The opening post is ridiculously over the top, like that cheerleader mom who tried to have her daughter's rival "hit" so her kid could make the squad - CERTAINLY not representative of all cheerleader moms.

Or southern moms who have kids who are greek...