Have you ever worked in marketing? Because it sounds like you don't know anything about marketing. That "lazy and contrived" slogan is the most recognizable throughout the NBA. I present some examples of 2017 NBA team slogans for you:

Trust the Process, All In, Grit ‘n’ Grind, Buzz City, See Red, Pursuit, and my personal favourite: Let's go Mavs.

Besides the horribly unoriginal Mavs slogan, none of these are a) particularly catchy or b) encapsulate the entire identity of a franchise. We The North is by far one of the better slogans in the league.

As for MLSE, the Leafs are the 3rd-most valuable team in the league, and the Raptors have risen in value 20% to almost $1b since Masai Ujiri took over in 2013. The overwhelming majority of that growth has occurred since the "We The North" campaign launched in 2014. I'd say it's working, despite your opinion on the matter.