Agreed. I don't wait until the last minute, and I don't blow deadlines. But that's not the point. To knock someone out of the running in July over a hyper-OCD desire to try to control workflow is beyond crazy.
I hope they lose a 3.9/520 candidate who can't meet the deadline because they are busy winning medals in Tokyo.
Given the number of people who turn them around super fast, the number of people who don't return them at all, and the number of people at all points in between, there is absolutely no reason to impose a strict deadline on their return prior to the ultimate deadline for everyone. This is why no other school does this.
In a parallel universe, candidates would refuse to submit secondaries that were not sent out within two weeks of primaries being submitted, but this is the sellers' market we find ourselves in. I think it's an unnecessary dick move, but everyone is certainly entitled to their opinion.