Hey there. We just wanted to chime in that you can avoid the account closure by logging into your account within the 30 days (since receiving the email pictured) and selecting the Cancel Account Closure link contained in the email. We certainly do not want you to lose access to your games or account so if you have any difficulties logging in then please create a support case with us. >> ubisoft.com/help
They're hoping this will actually entice people to come back. Following that "get people in the door first and then worry about what you'll sell them" business model, it's the same logical reason that Costco has super cheap hot dogs that they lose money on, and Epic Games has free games every week. It's just to get you to into a position where you can be marketed to.
That's the more "amicable" business strategy though. The more sinister possibility is, well, a constantly running app (the Ubisoft launcher is configured to start on boot by default, and even if you turn that off it spawns a background process as soon as you click on it at least till you reboot), always online with full user permissions and filesystem access is a very powerful thing, you've gotten yourself a pretty capable Trojan virus that people are willingly installing and granting whatever permissions you need! Plenty of Windows users are also in the habit of using the admin user with system access for literally everything, which makes it even easier for them to exploit.