To be clear, they're not banning the app, they're banning ByteDance from having offices in Canada
replies(4):
1. Show the current government is doing something after the CSE said the Canadian government has been breached by China's MSS [0]
2. A response to China for breaching Canada's systems.
3. A way to get a quick win to make bipartisan China hawks across the border in the US happy.
[0] - https://www.cbc.ca/news/politics/cse-cyber-threats-china-1.7...