There is a difference between an information and a warning. If I am entering information on an unencrypted connection on the internet I want a warning. And I don't want to get accustomed to that warning, because if it happens I want to be alerted.

If the same thing happens in my local lan I don't want the same warning, because if I get the same warning I will start to ignore it, and not only when I'm in my local lan.