Why not allow everyone to purchase the crown gems, then? If everyone who doesn't want to gamble but would buy the items directly participated, it would result in more happy customers and more money for ZOS all around. I wouldn't expect such a thing to be inexpensive but it would give an option that currently does not exist for people who strongly prefer fixed prices.
I like the system because it is purely based off RNG, meaning it is adding rarity to the apex mounts.