The solution is to teach those users how to use sudo properly, not to teach them to be even more insecure than they already are.

It's like saying, "I don't need to wear a seatbelt because I already drive my car at 90mph everywhere, so the seatbelt wouldn't make a difference in a crash anyway."

If you have sudo set up without a password, fix that crud! This is not a new concept, the Linux community has been warning people about unprotected root access for over a decade.