What Drath Malron said -- it's immersion breaking.
I'm fine with the PC being the only person able to use them -- walking everywhere gets dull -- but why are we able to do so? If the ability to use the portals was a reward for finding the skeleton that would solve the immersion breaking aspects of the camp and the portals.
"Use this phrase to open the portals. The first of the exit points will take you to an ideal place to set up camp -- it has access fresh water and its entry points are easily defended. I will meet you there."
