ESPN is horrible. I build auth systems for a living, and I have given up logging into ESPN on numerous occasions because I can't get through all the steps.
As recently as a few weeks ago I was watching a game downstairs, and it went into multiple overtimes so it was getting late. I decided to go upstairs to bed and tried to watch it on the AppleTV in the bedroom. I was logged out. So I spent over 10 mins trying to log in before eventually giving up and watching it on the iPad, since I happened to still be logged in on that device.
It is for the best, because even after you manage to log in, trying to navigate the menu with the AppleTV remote is an exercise in frustration anyway.