The EX Pokemon were already going on for a while and kids knew they were really strong, but to have an even stronger version of that, I think that got a lot of people excited. 2
Then as your vehicles deal combat damage to your foes, you exile that many cards from their library and you can play them, although there is no mana-washing here, so in a mono-Blue deck you might find it rough to cast non-Blue, non-colorless cards
I like having unusual and/or rare cards
This doesnt just impact graveyard decks, but it also gives a midrange-control deck card advantage in the late game
But for both set one and two of Lorcana, it was the bronze rares that established themselves as staples with the board wiping Be Prepared of set one and the hasty 4 willpower and three health Madame Mim, Fox of set two