Google keeps my docs on the cloud so it's obvious why I need to authenticate. Wholly local desktop or tablet apps have no business asking for my email because

Google keeps my docs on the cloud so it's obvious why I need to authenticate. Wholly local desktop or tablet apps have no business asking for my email because they have no credible need for it. Authentication is borne by other elements (the OS, my physical security, etc). As soon as an email dialog pops up, it breaks my mental model of "local software" and I worry about what the software is doing under the hood. Especially if it doesn't come with any rationale about why it's asking me for it. e.g. Will I get more spam (and yes, the quarterly message you send me about product updates is spam in my book unless I explicitly asked for it - you're not as important as you think you are), does it phone home, what other telemetry is being siphoned off, etc? It's a red flag that smells wrong, and signals the software isn't behaving according to my expectations. How would you feel if you walked up to a car that asked you to punch in your email address before you could open the door to take it for a test drive?