In any sport, there are two types of gameplay: 1. For fun. 2. To determine the strongest.
Something to think about: CIS 2011-2013 was held on Wargames Tavern (WT), and there was no alternative championship on SoD (Shadow of Death) of the same scale, nor was one planned. It would seem that these were the rules for identifying the strongest. But... the majority continued to play on SoD.
Another thought: in CIS 2012-2013, mirror matches were played a lot, especially in the semi-finals and finals. And if it wasn't a mirror match, it was 8mm6a. But we open the WT chat and the seasonal games... it's all Jebusick.
Do I need to keep hinting, or will you figure it out yourself?