As has been discussed many times before, private courses get an overrating boost of 0.25-5.0 out of gratitude to the owner, and that one can usually partake without fear....and the imaginary "vibe" that people feel when on these courses. These courses often get a pass when they lack things that public courses get hammered for lacking (good/consistent tee pads & baskets, signage, bathrooms, parking, safety, etc...)
If you are rating the overall experience, I guess that is fine. That is a recreational rating based on the game of DG.
But if you are rating how the course effectively tests the skills of the thrower (the person competing against the course - the sport of disc golf), those are not valid considerations.