As a counter point, I've been running a service like this for 2 years. I had one person mildly complain in the early days and the thousands that have signed up

As a counter point, I've been running a service like this for 2 years. I had one person mildly complain in the early days and the thousands that have signed up after haven't said anything about it. Emails go through instantly every time and they rarely get logged out. I get a lot of feedback weekly but it's never about the signup/login process.