nb, I don't think the # of upsets -- in real life or in HD --is indicative of whether the committee has done a good job w. seeding or not.
You could play the same exact bracket out (real life or HD) a number of times, and you'd have some occasions with lots of upsets, and some occasions with very few. The diverse outcomes wouldn't change whether or not the committee did a good job.
(Do we think VCU or Butler were underseeded or that the committee did a bad job on them because they ultimately made deep runs? Of course not. And certainly not any more than the 1 seeds losing means that they were overseeded.)
If anything, if we are seeing an increase in the number of chalk brackets in DI, I think it's simply indicative of a sharper divide in talent between haves and have nots.