It is quite obvious. SDS figured out that they sell more stubs at the beginning of the year, the season, than at any other time. So someone at SDS, who has since surely been promoted, decided why not have 4 starts of the year (seasons). No one will have cards again and we will see that green flow in 4 times instead of just once.
This primarily affects DD and people who want to play their favorite team. Competitive DD players will be throwing cash at the game at the beginning of each season when they no longer have the best cards. For me, how am I to make an all time Cubs team? By the time I have a Cubs team together I will have to start all over again. Sure those cards will be better, but by the time I have the new team together they too will be taken from me. Over and over again. Non-Core cards will be worth nothing except for collections. No one will have their favorite team put together for any significant period of time.
And why? So SDS and Sony can keep the cash flowing in at our expense (literally). Oh so you don't want to spend money at the beginning of each season? Good luck with that.
SDS goes the way of EA.