Indeed. People should rather review and make sure their registration and login forms work seamlessly with password managers, at least the popular ones (lastpass, 1password, etc).

All too often I run into a form that is either not auto-filled or where some javascript magic fails when it's autofilled (e.g. the page claims "password too short" until I fake some keystrokes manually).

Hint: If your login procedure is annoying then I'll come back less often (or not at all) for that reason alone.