I agree that Tierney is likely the largest single factor.
But, even with the best face-off man in the history of the sport, the Pioneers made the FF 2 of the past 4 seasons. Compare that to SU's FF run, or stretches where JHU, Princeton, and UNC have been regulars on Memorial Day weekend, and it's easy to see that's there is much more parity than has been the case in the history of the sport.
I think this is perception without much basis in fact. It's a good argument for teams like Syracuse who aren't on top anymore. Point to parity instead of the coaching staff.
There have been 46 titles and only 10 teams have ever won a title.
The final fours have been dominated by the same teams; whether the 80s, 90s or 2000s.
Let Define our blue bloods - Syracuse, UVA, Hopkins, UNC, Duke, Maryland, Cornell, Princeton(Denver), Loyola,
It should be noted both Loyola and Towson had FF appearances in the 90s and both played in title games. You could argue both are old blue bloods.
(when did parity become 'a thing' is there a year onward we should examine?)
The Final Four has slotted 76 teams since 2000.
Here are your outliers with appearances:
ND - 4
Towson - 2 (had title game appearance in the 90's)
UMass - 1
Navy - 1
Delaware - 1
Brown - 1 (had a FF appearance in the 90's)
Ohio State - 1
Yale - 1
Albany - 1
Outliers - 13 appearances
Blue Bloods - 63 appearances
I won't deny that other schools are more competitive now and there's more schools playing but parity is not affecting the blue bloods the way some people think it is.
Syracuse comprises 9 of the 63 appearances but zero in the last 5 years. We're struggling now with the outliers (Bryant, Towson, Army) as well as the blue bloods. For Syracuse it's an across the board thing.