With a loading wheel you can't really do that... You can only report the issue saying you can't get in, and that really doesn't give much information to the support team at all.
If a user or users see a loading wheel, they can’t see any progress and don’t know if the games even loading up at all. This gives them no incentive to wait. Meaning if it takes too long for the game to load up they'll promptly close the application (game) and stop playing it.
I am aware that Nebula did have a progress bar (loading bar) at some point in time, but replacing it with a loading wheel seemed kind of a step backwards in my opinion.