I am willing to live with this case (some random person who is not used to presenting on a projector forgetting to mask his password) for MY personal utility.
This doesn't make sense -- why should the random person suffer at all? Your personal utility would be equally well-served by a browser plugin that made your password fields visible.
It's not technically difficult, so if it doesn't exist, it wouldn't take much to create.
My personal utility would not be equally well-served - because it would involve finding & installing said plugin.
Meanwhile that random person who can't be bothered to click on the 'mask password' checkbox is just someone I don't really care about. His 'suffering' is entirely avoidable.
On a more serious note - I believe the number of individuals who benefit from this change (everybody typing in a password) would receive sufficient benefit to outweigh the cost incurred by the few who would bear the burden (someone giving demonstration and forgetting to click 'mask pw' button).
It's not technically difficult, so if it doesn't exist, it wouldn't take much to create.