I've been looking into roasting my own coffee beans. Interestingly enough, the only smart roaster I've found only works with Windows desktop (not iOS, Android, MacOS, or WP). That's fine with me though.
Starbucks is among the worst coffee. I don't understand the appeal. Many gas stations have better quality coffee than Starbucks does and the price is significantly less. There is a local coffee chain here in Pittsburgh called Crazy Mocha that I like quite a lot better, and many independent coffee shops as well. As for McDonald's, I refuse to go there for anything other than to use the restroom. Their food quality is subpar, and while their coffee might taste better than Starbucks (I refuse to try it so I don't know), they don't even properly clean their coffee machines; their employees tend not to be very hygienic.
As for the Starbucks app, I think they are just temporarily holding off until Windows 10. The e-mail the OP posted does not say 'never', after all. Although I'll never need the app, I hope they do at least port the iOS or Android app to Windows 10 to appease those who are requesting it. It appears to be very simple to do and if they can publish it in the Amazon store, they can in the Windows store too. I don't think Starbucks has any grudge against Microsoft or Windows like Snapchat does; it's just a business decision they made to maximize their profits on the horrible coffee they overcharge for.