Wario's popularity really shot up when Intelligent Systems created many of the WarioWare games. Intelligent Systems was the developer of 6 Golden Coins way back when it was released on the Game Boy, so technically they can be considered the creator of the Wario series. Intelligent Systems is a first party Nintendo developer, meaning that they're a Nintendo company in the same way that Nintendo EAD is. WarioWare became so popular that it is now its own spin-off series, which is without a doubt even more popular than the platforming games which started his career off.