I mostly agree there. Though at least the School of Friendship would be a logical place for the CMCs to practice their talents as Cutie Mark Counselors - many of the students there would be in the age range where they’d have either just obtained their cutie mark, or be close to getting it. But you’re right in that it was pretty disappointing to see their individual talents swept aside in favor of a career they hadn’t shown much real interest in (outside of one blink-and-you’ll-miss-it line of dialogue from “The Last Crusade”).
Then again, there was a statement from one of the staff to the effect that the future was meant to be open to interpretation, and the Mane Six established that it is possible to teach at the school while holding another full-time career. So for all we know, Scootaloo has a pair of prosthetic wings and a Wonderbolt uniform stashed in the faculty lounge.
And it did feel odd that Pinkie Pie was the only one of the Mane Six to have an actual canonical no-room-for-interpretation spouse and child. Though at least “Baby Cakes” had her rise to the challenge of baby care and continue to serve as the Cakes’ babysitter, so it’s not entirely implausible that she’d eventually think about making one of her own.