Better views of night sky from Hawaiian beaches than Hawaiin mountains?

I am looking for a stargazing tour from the mountain Mauna Kea (Hawaii). Then I found this guide who claims the view is better from the beach. I know the view for humans eyes isn’t the best at the 13,000+ foot summit because of oxygen deprevation, but I thought the views halfway up the mountain would be better than fron the beach, due to less atmosphere. Am I wrong, or is this advertisment wrong?