This almost makes it sound like you wouldn't mind users who have an account creating a new account each time instead of logging in, because that would increase

This almost makes it sound like you wouldn't mind users who have an account creating a new account each time instead of logging in, because that would increase the number of sign ups. I don't think you actually mean that, but the idea came to mind, after a more vague feeling did. To say that sign ups are more important than ability to log in, to me, feels like the quality of the product has lower priority than sign up metrics. Like, if you care more about how many people sign up, than about how many people actually use it (even once), then it seems like the product isn't being made to be used, but rather for some other purpose.