As a user, every time I want to log in to my Gmail or Instagram account, I have to wait till the page is fully loaded, then "click" on a button that directs to the log-in page. Why don't they let us log-in in the first page?
Actually, Gmail starts with the login page, if you load it first time.
Instagram starts with registration, which also makes sense to me considering you are not likely to log in too often.