I think Hales should have to suffer the consequences, and missing a WC is a reasonable punishment.
He was extremely lucky to not face legal action over the Bristol incident, and you'd think would be attempting to be squeaky clean at the moment.
The issue may be, if true, that Hales management team claim to have been told that a ban would not affect his place in the WC squad. It's a big if, but if true then that is pretty poor from the ECB themselves.