The original AoS ruleset really did not work as intended. It contained fairly serious logical errors as a result of excessive simplification, such as infinitely stackable bonuses that allowed guaranteed success and failure on hits, saves, mortal wound dealing etc, the ability for units to shoot without restriction or penalty while supposedly locked in combat, the fact that you could trivially snipe heroes with shooting as well as the total absence of army building rules of any kind.
The usability of warscrolls also has nothing to do with the ruleset itself, presenting all of the rules for a unit on the page that describes that unit can be done regardless of the ruleset that is being used. This is an issue of presentation of rules, rather than of the rules themselves.
Obviously the GHB second edition fixed most of these problems in a way most people found satisfactory, but 100% of those problems existed as a result of simplification for the sake of simplification with no regard for how gameplay would be effected.
It's to the credit of the current AoS rules team that they've done a complete 180 with their approach to game design and taken an approach emphasizing consistent rules wording, clarity of intent and balance, but the first version of the game was an unplayable shitshow that did not work and everyone knows it, even GW.