Pedantic
Legend
Right, we're leaving out steps. The proposed structure is creative agenda->design goal->mechanic. Pointing out a mechanic doesn't serve an agenda is pointless (in no small part because RPGs still struggle with successful implementation all the time); what was the design goal the mechanic tried to implement?"Not become a slog" doesn't really fit into the creative agenda buckets, as @Pedantic mentioned before.
It's more akin to bounded accuracy in 5e, or the decision to not allow advantage/disadvantage to stack and cancel. It's for the goal of "ease in play".
4e's minion rules points to a missing design goal for simulation (something like "entities in the game should have consistent mechanical representations") not a failure of implementation.