As a former avid CCG fan allow me to try my hand at explaining why this is problematic:
At the core a CCG is fun because it produces different outcomes and different scenarios in just about every game played. This is why buying boosters and constantly improving your deck is supposed to be incentivized by simply playing the game. As with any game that has a skill component and a luck component the goal of a player is to minimize the influence of luck through use of skill.
With a CCG skill often presents its biggest impact in the deck construction itself. With widespread information and communities on the internet deck lists are easily attainable and thus the only limiting factor for cardboard CCGs is the availability of the cards. With that barrier removed the last skill aspect remaining is in game skill, which while it can make a big difference often leaves you at the whim of the opening shuffle.
The end result of this situation is that skilled players will quickly boil down the card sets to at most 3 deck types with minor variations in each. The result is that every match you play will boil down to an extremely small subset of scenarios determined by the 3 decks. In other words, very quickly things will either be so repetitive that there is little point in playing again or if you refuse to copy cards in this way you will find yourself losing...often....and horribly....
edit: I will add that there is no gaurantee this is the fate of the EoJ, but I can tell you that this issue where major deck types dominate the landscape are also major problem in cardboard CCGs where copying is MUCH harder to begin with. I cannot imagine it gets better when that process is made easier. And many of those cardboard CCG games have significantly more cards to draw apon which increases the variation.








