It's not a security measure because the original comment spoke about how they couldn't even search for the login inside of the autofill icon. I've had that issue too and it's very frustrating. Yes, it makes sense not to show it by default, but to disable any sort of search functionality inside of their new autofill UI is annoying.

Edit: This was not an issue before 1-2 years ago when they pushed massive feature updates. It used to be Ctrl+\ or Cmd+\ to autofill and boom, the login was filled. But NOW they have decided to drop a "1Password X" browser extension that throws itself into every single login item on the web and constantly harasses the user any time they use keyboard shortcuts to navigate. Typing an email address and see your Firefox/Chrome/Safari autofill show up with a dropdown of emails to choose? You can't even use the arrow to go down and choose one; 1Password X will rear its ugly head the minute you hit the arrow down, and it'll either prompt you to autofill something or save what you just typed into 1P.