I can see both sides on this one. In many ways a PHEV is redundant, effectively having 2 separate drivetrains, more cost, more weight, more materials to build the car. On the other hand I still see the need for the ICE backup, I still live in an area where I would be locked to our city in a pure EV, a PHEV would reduce our carbon emissions somewhat while still allowing us to travel to other centers. At the same time we explored both the cost and CO2 reductions of us purchasing a PHEV, and can't justify it now. We will just make the leap directly to EV when the time comes to replace our vehicles, and once the charging infrastructure exists here.
I believe current PHEV's are built using the wrong design criteria, first and foremost they are ICE powered vehicles, that have had a motor added with enough battery storage to drive a short range on electric only. PHEV's need to be built as EV's, with a small ICE engine and generator as a range extender. A small 1.0 liter 50 hp engine would be sufficient as a generator for most small cars, which would free up a lot of space and weight from a conventional ICE drivetrain for larger batteries and bigger motors.