Lining it up with the HSX seasons means fewer weeks, which means less opportunity for a single winner. The season from May 15 to September 15 would be especially predictable.
The scheduling changes hit especially hard this season because I brought forward the entry date - there were a bunch of them made right before Christmas.
But the reason I brought forward the entry date was so that Rogue One's OW wouldn't be known. One learning experience fom the first comp was that IDAY2's disappointing weekend gave an advantage to those who made their picks late. (Of course people have the option to change their picks, but barely anyone took up that option and those who did had to re-enter)