Konami is indeed an expert. They won't let certain decks shine for too long, not only because it causes boredom to many players, but also makes them hard to sell new box. That's why they REGULARLY update the banlist
I spent so much money buying 3 copies of most UR for my Dark Magician and Invoker decks.
Many players just rage quit when they see at least 2 copies of Molehu or Dark Magic Circle, giving me free victories even when I might have lost.
Everyone who intended to play those decks have 3 copies of those UR.
Because of this Konami might limit them, forcing me to buy new decks.
So far Konami never hit box's UR. They are greedy about money but at least they still have respect for player's money/effort of collecting multiple copies of UR from the box