I understand that we all play things different in our home games so that's not really the issue here. It's the default assumption of the game. I don't always play with people I know or with my usual group. Sometimes I will guest DM so I rely on the default of the game. I believe that if the material in the DMG was for a players then it would be in the PHB and not the DMG.
Well, you've answered your own question, then. In your games the DMG is off-limits to your players. Tell them that! I'm not sure what the question is now....
