This is why theres no grinding left in the game. Every single time that you ask people to do a specific thing in the game, they complain. Its always "why cant I just do only the one thing I like and get all the rewards"
There are different levels of players in this game and, as this is several different offshoot games in one, you can’t expect everyone to be able to play everything. You already have programs like ranked and events where you can earn cards exclusive to that area. But if you have a program you expect everyone to play then make it something everyone can play, not only a segment.