Make launch at login opt-in on desktop

This a textbook case of Chesterton's fence: before tearing down a fence, find out why it was put up. This fence went up because plenty of people never figured out how to enable launch at login, kept missing their notifications, and let us know they weren't happy about it. So on-by-default is what causes the fewest headaches. It's also one click to turn off. Hanlon's razor says never attribute to malice what's adequately explained by stupidity. In this case it isn't even stupidity, unless listening to user feedback counts. Can't make everyone happy! That said, I'd be happy to implement a setup step on first launch where you choose this upfront. Have a triply nice day!