You make a compelling argument, but I just think a better balance could have been struck over the years.
And obviously, this is coming from a place of my personal preference, not objective fact. Of course Diagon Alley is better for the resort overall than Jaws. Jaws, as a ride, blows Gringotts out of the water, however.
Gotta echo Drew's thoughts here:
Diagon > Amity
Jaws > Gringotts
And I kinda agree...
This would be an incredibly depressing outcome, especially considering what their original Nintendo plans were.
Might be for the better, even though it sucks to wait.