I find this way of doing it highly annoying when I come back to a site I haven't used in a while. First having to enter my email to get my username and then enter my username and email to reset my password.
Why do sites split it up like this? Is it believed to be better UX? Better security?
I mean, the weak point is my email in both cases, so if someone got a hold of that they would get both the username and the password anyways. So why not just combine it into one function where you only need to supply your email?