it is probably the lawyer in me...
You have just bought an $80,000 to $130,000 Model S. I'm guessing Tesla is trying to force its car owners to have a fully licensed electrician install a new fully dedicated 50 amp circuit with a new breaker and modern 14-50 receptacle within reach of the Tesla provided charging cord. Heck, they even give you an adapter for that. As a result, you are forced into professionally installed new circuitry, with a brand new 50 amp receptacle close to your car and with quicker charge times than 30 amp circuits which the 10-30 or 14-30 receptacles provide.
Maybe Tesla just has our best interest at heart. (;>)