Well, he wanted to save the surplus to fund the extension of the Sheppard Subway, instead of using it to keep some schools, parks, libraries and other city-operated services open. He also opposed the less-expensive light rail transit option that they suggested instead of the subway.
I almost forgot to mention that scrapping the plastic bags wouldn't have happened if he hadn't brought up scrapping the 5-cent bag fee. I could go into more detail, but that would be Fratching territory.