So... to prevent Divine Smite from being made a spell, you would have wanted the paladin redesign to lose spellcasting entirely?
And you don't think that fundamentally redesigning a half-caster into not being a caster at all, and losing their entire spell list would not have been a MASSIVE design challenge and a MASSIVE disruption to the game? Sure, they could have done so, but they also could have moved from 1d20 to a 2d10 system, I don't see that as a reasonable direction for them to take though.