houser2112
Explorer
The business opportunity was the abandonment of the 3x rules framework and existence of the OGL creating a vacuum that could be exploited. The "existence of legions" had to be proven through taking the risk of pursuing the opportunity. There's plenty of examples should we look for them of folks complaining about something and not converting that angst into real spending.
I'd say the existence of unhappy 3.x fans was more important to the success of Pathfinder than the OGL. The existence of the OGL would have been useless without the demand for product utilizing it. They would have been harder to satisfy without an OGL, but not impossible.
I seem to remember segments being a thing in 2E, but I'll take your word for it. I have no desire to delve into 2E arcana.Go back to 1E and read how combat flowed from an initiative standpoint. (10 phases to a round etc.) Then read 2e. Completely different flow.

Out of combat is informed by combat. So if you say - I'm going to go with map based combat only and structure AEDU, then that resolution format will affect everything else. D&D is a combat game. 4E was far more of a radical shift and required to be different from Pathfinder and the previous rule set to show value against the competitor.
So you agree that 4E substantially changed both combat and out-of-combat.
I agree regarding resonance. Right now it doesn't make much sense to me, but it depends on if there are other structures that essentially treat living things like mana batteries. If it's the only available use of the mechanic it sounds silly, but if the mechanic is a small part of how magic works in the game system then I'm ok with it. Just has to be consistent.
I think 5E's solution to the spells-on-a-stick "problem" is more elegant than what I've seen of Resonance.