I would rather not assume that he is complaining. I would rather say it is simply stating might what happen, based on need (as you suggest). Although, a busy supercharger would often lead to cause for complaints.
The good news about this SC is it's location, as mentioned above. If it is busy, it is likely so by people actually traveling somewhere, rather than shopping at a mall or having a leisurely meal. There is not much incentive to leave a car charging for more than what is needed. Just to be clear, I am not opposed to locals charging. I am opposed to those who leave there cars for several hours while they work nearby or go to a movie, etc.