First, what is standard 50A charging? I've never heard of this. I also don't know what you mean by twin 50amp charging?
Second, no one is being pushed to buy the supercharging upgrade. It is standard -- no extra cost -- in 85 kWh battery packs and is an option for the 60s, with folks who live in areas that don't have SCs not buying the option, for now. People can decide for themselves whether they want to spring for the option or not. Really a cost benefit decision and weighing the value of your time and the potential increase in resale value long-term. To each his own.
Third, for those 60 owners who didn't buy the option, they had a clear choice: either purchase it before taking delivery for $2K, or $2.5K after. Tesla has apparently made a business decision that enough 60 owners aren't opting for the $2.5K after-delivery option, so they've lowered the price. I don't see anything wrong with that or any admission of prior wrongdoing. Just a business decision reflecting that few people were taking the after-delivery option.
Fourth, why on earth would Tesla want to make L2 chargers, that any EV could use, available at all supercharging stations?? Tesla never said that "regular charging" was available at all supercharging stations, but more imporantly, "regular charging" is available just about anywhere in the U.S. and often for free -- if you want to sit and charge for hours and hours and hours. Why do you need to go to a Supercharger location just to use a L2 charger??
Finally, FWIW, at the Gilroy superchargers, there are a couple of Level 2 chargers adjacent to the Tesla superchargers. So if some 60 owner who didn't want to pay for the supercharger access wants to pull up and hook into Level 2 and watch all of the other Model S cars use the superchargers while the person using the L2 charrger waits all day to get a full charge, they are welcome to do that. Also, at the Atascadero superchargers, there is a Level 2 charger (with 70A no less) in the same parking lot.