I already got the Hades accomplishment for getting the in-game idols without the the use of websites and I personally don't think too many people received all their idols through AR Card sites since there's not too many of them actually have all the cards.
I scanned in the cards I got with the game, then I ordered 2 packs of cards from ClubNintendo about a week before I got the game. They took so long to arrive that by the time they did I had all the idols, so I guess their only purpose is for collection, or the gimmicky battle thing. I alos scanned in Palutena Rare, Dark Pit-Flying and Rally Cry, but they aren't counted in the achievement.
So you're not only complaining about an optional feature, but abuse of said feature. These cards are meant to be purchased. You have absolutely no reason to scan them from a website unless you want to.
http://i.imgur.com/rbBq9.jpg Come to the board in my quote for math discussion and pretty much anything else.