Er, no, you're making things up here. The SAE only claims that the receptable on the car can be made to accept existing J1772 connectors, not the other way around. On all recent plug-ins and EVs I've seen, only the Nissan Leaf (ironically enough) might have enough clearance around its J1772 receptacle to accept this new proposed plug. Chevy Volt, Mitsubishi i-MiEV, Prius plug-in, Ford focus... forget it.
(and to clarify, the charger all those have on-board is single-phase AC, not "2-phase")
Regarding the reality of DC fast-charging: first, it's here today (despite the SAE, not because of it) and it works very well. And yes, cables are thick and heavy, but certainly not more than a gas pump tube and nozzle.
Multiple automakers (Nissan, Mitsubishi, Subaru, Peugeot..) and charging equipment vendors (Eaton, Fuji, AeroViromnent, Efacec, Andromeda etc etc) already implemented another, existing standard, CHAdeMO, starting years ago. (none of them use capacitor banks btw, just a regular commercial electrical circuit).
The batteries in tens of thousands of EVs already on the road handle fast-charging just fine, thank you. Not just at fast-charging stations but also every time the vehicle slows down btw (regenerative braking happily pumps tens of kW back into the battery).
Second: unlike you I think that DC fast charging is critically important for wider EV adoption.
The two biggest hurdles for EVs today in the market are initial cost and limited range.
Batteries will remain pricey for the foreseeable future, so cheaper EVs will continue to come with relatively modest packs (say 16 to 30kW*h), and therefore only 50 to 120 miles range. Extending this range by recharging is only practical if it's quick enough, ie counted in minutes and not hours like with traditional AC charging stations -- I really don't mind stopping 15~30 minutes on an occasional 150 miles trip, in exchange for that lifetime 80%+ discount on "gas", and I could see such compromise being totally acceptable to a lot of people.
Now those 50kW+ chargers are big heavy expensive beasts, so keeping them outside the car (hence DC at the connector), usable by more than one vehicle, makes complete sense.
So yep, DC fast-charging is a very practical and cost-effective way to lift the range constraints otherwise inherent to more affordable EVs.
Freedom and $$ -- you were calling this 'irrelevant to most'?