Did I imply that? Whoops, I guess I forgot to add a bit on the end. I think that Wario turned greedy after Kamek left, when Bowser charged him money for staying in Koopa Castle. That meant Wario was dead set on trying to pay Bowser off. When he did, he realised that money was good. Therefore, he needed to get more to make a good living. He originally thought to get Peach's coins, but there was one person who he hated more- MARIO.
After losing to Mario, though, he decided on getting other people's money. However, when he was terrorising Toad inside woods on his property, Toad began to fight back. However, when Wario was on the brink of losing again, Yoshi came and saved him. Angered at being saved by such an innocent-looking creature, Wario blinded Yoshi, Peach and Mario by putting buckets on their heads. However, Luigi saved them, with the help of Wanda, and Wario captured Wanda. He stole her magic Wand, and conjured up riches. He had also made millions in software. After losing all interest in Mario, he decided to settle down, until he heard Peach had been kidnapped, and there was a reward... he thought it was Coins, but it was just a cake... but from this day forward, Mario and Wario maintain a love-hate relationship (And Wario loves Peach's cake!!).
It''''s funny until someone gets hurt. Then it gets hilarious!