Here are the rewards available for the free pass:
For an endgame player, that’s what? 2 pulls on a Faction portal, 6 Diamonds, 4 Epic Ingots (You’ll need a lot after this update), a pittance of gold and glory, resources like Traitstones that nobody can run out of, and… 70 gems worth of keys.
Compare that to an exclusive Mythic. I’d pay several thousand Gems for that, but a $10 pass is extortive.