Disagree. Even bullets shouldn't be displayed while the user types the password. Why should a security camera in an office know that the user's password length is ten, twelve or twenty nine characters?
On the other hand, if I start typing my password too soon after the login box appears on my laptop, it eats the first character. I would never have worked out why I was finding it so hard to login if the password box did not display bullets. (See also dodgy keyboards.)
If you cover your hand, the problem space is still small enough to guess just based on where you are covering and how long for.
Only systems that do not use passwords are viable if you are being closely scrutinized. e.g. entering only selected characters from your passphrase.