WRONG.
-Wario Land 1 was about Wario finding the Peach statue so he could blackmail Mario in return for castle funds. The statue was stolen by the pirates and hidden on Kitchen Island. At the end, Mario shows up and takes the statue, but Wario manages to pay off a genie with all the treasure he found to build him a castle anyway.
-Wario Land 2 was about Wario having his new castle invaded by the pirates from the last game and all of his treasure getting stolen. There's even cutscenes between each stage showing Wario chasing the pirates.
-Wario Land 3 had Wario getting sucked into a world inside a music box and having to find a bunch of treasures to release a god figure from imprisonment so he get sent back to his own world. The god figure turns out to be the game's real villain who was just using Wario as a means of returning.
-Wario Land 4 was about Wario reading an article in the paper about an ancient pyramid full of treasure, so he goes there and winds up saving a princess and stopping and evil she-demon in the process.
Did you even play these games?