I have a guess. Because ACC fans are used to being dominant, they are NCAAT obsessed. Because the NCAAT selection weighs early season games equally, and the ACC has a recent history of enduring tough early season losses, ACC fans get down on their conference because of the negative impact of those early losses on the NCAAT selection algorithm.
But it seems to me that a moderately savvy fan should know a good team when they see one, algorithmic computer generated rankings notwithstanding.
This would be my guess as well.
Here's the last 5 (played) NCAAT Sweet 16 results (Invites/S16 Teams) by major conference (ACC, Big East, B1G, B12, P12, SEC).
ACC: 2024 (5/4), 2023 (5/1), 2022 (5/3), 2021 (7/2), 2019 (7/5) - Total (29/15) -
0.517
BE: 2024 (3/3), 2023 (5/3), 2022 (6/2), 2021 (4/2), 2019 (4/0) - Total (22/10) -
0.455
B1G: 2024 (6/2), 2023 (8/1), 2022 (9/2), 2021 (9/1), 2019 (8/3) - Total (40/9) -
0.225
B12: 2024 (8/2), 2023 (7/2), 2022 (6/3), 2021 (7/1), 2019 (6/1) - Total (35/9) -
0.257
P12: 2024 (4/1), 2023 (4/1), 2022 (3/2), 2021 (5/4), 2019 (3/1) - Total (19/9) -
0.474
SEC: 2024 (8/2), 2023 (8/3), 2022 (6/1), 2021 (6/2), 2019 (7/4) - Total (35/12) -
0.343
Not sure what all we can take from this.
1) The ACC is as competitive as any other conference, maybe more so.
2) The more teams a conference gets (obviously) the lower the percentage making the S16 will be.
3) There are 2-3 conferences that routinely place fewer teams in the S16 yet get more invitations.
4) The metrics being used are pretty obviously trash.