Two things are equally true.
1. The Big East is nowhere near being a mid-major conference.
2. The ACC isn't close to being the best conference.
Mid-majors don't have multiple top ten teams, a national player of the year candidate, multiple freshmen All-American candidates, and a top 3 conference RPI.
The ACC got abused by the Big Ten in the challenge, and are far behind the Big XII, and doesn't have close to yhe depth the Pac 12 does.
Pitt went where they needed to go for football reasons, but the basketball program isn't better off because of it. Both recruiting and attendance have fallen off since the move. You can spin it any way you like, but that's the truth.