Superchargers were designed for travelling, with most charging to be done at home. Early on this was made clear but as time has gone on there is no mention of it in official literature - it is only alluded to when Tesla started to restrict charging times and implementing pay-per-use and idle fees.
Whilst, I am sure it is convenient for you it really isn't for those that actually need the charge to complete a journey and are forced to wait for your car. There has been considerable frustration in Sydney from those of us trying to get a charge, only to sit in the car waiting for bays that are taken by UBER and Hire Cars. Yes, technically that was the deal with unlimited supercharging, but is completely against the spirit of the arrangement. If everyone had the attitude like yourself that they can use the supercharger network for all charging needs (which we are all entitled to), the network will be hopelessly overloaded. Waiting for an hour before plugging in at every supercharger may change your mind..
There is also evidence that supercharging only, is bad for the battery and eventually Tesla has throttled supercharging speeds for these cars.