Customer Portal Button issue

Stupid question, but when someone sends an email to the support email and a ticket is automatically opened, the default Contact Notification templates for things like Acknowledge contact on receiving a new ticket and Acknowledge contact on receiving a reply contain a string ${Cases.CUSTOMER_PORTAL_BUTTON} which places a button link on the email they receive. this takes them to a login screen where they cannot log in or register so they can view their ticket, yet the button says "View Ticket"

What was the idea behind this button if the customer is unable to actually view their ticket?

I took this string out of the templates but I'm baffled as to why it's in there in the first place.