I don't imagine this is intentional so much as the result of years of forced-to-be-console-friendly code piling onto itself like the fat of an 800 pound man layering up just so and crushing the breath from him while he sleeps.

I suspect Tier II en-spells were a Development Bro's attempt to work around the mutual exclusivity of additional effects, so in addition to being horrible themselves, they can be considered an ill-omen.