The Tesla Model S is also a very heavy car, at 2100kg. However that weight is somewhat offset by its placement, right near the road using a flat floorplan housing all drivetrain components.
While the weight can be cancelled out in a straight line because these hybrid drivetrains can provide monumental straight line performance, the weight is still there for turning and braking.
Turbos go around the weight issue - in fact, they can make for much lighter powertrains with a smaller displacement for a superior performance. The main problem with turbos, in Ferrari's perspective, mostly relates to the altered emotional connection with the car. No more 9k RPM revving motors with a godly sound, but something tamer (like the McLaren MP4-12C). If you ever got to drive a current generation Ferrari motor, you'd understand instantly why they are so adamant on preserving its character.
Some of the more sophisticated work here is also being done by Porsche in their LeMans program, which has (as I understand it) a uniquely complex turbo/hybrid setup.
I think it's really exciting. Considering this type of usage — mostly transient stuff — it's tempting to think of a system for sports cars with a supercap energy store that's lighter weight than a battery store. Toyota use supercap stores in their LeMans car, I'll be interested to see if that trickles down anywhere.
1. http://www.fueleconomy.gov/feg/taxphevb.shtml because someone buying a $845,000 car which gets 20mpg city / 24 highway and carries 2 people definitely deserves a $3,667 tax break for reducing emissions
I was just speaking towards new paths in getting the most out of ICE-centered power systems, that an alternative power store and MGU can uncover better turbocharging options vs. a purely mechanically coupled turbine/compressor. These technologies are being developed at the less price-sensitive high end of the market, just as Tesla is doing with an all-electric drivetrain. They started at 100K+ roadsters, developed to an 80K luxury sedan, and are developing down market from there. I think it's totally appropriate to encourage a shift in industry standards, as you say, with incentives in this segment of the market (let alone where the Prius sits). It's a bit of an absurdity with the Porsche, but take heart that there are only 918 being made…
As far as what kind of sports cars we should be encouraging, even mid-market cars are so fast now you really can't enjoy them on the road. That's why cars that emphasize a fun driving experience at still-sane speeds are the most interesting to me now, like the FR-S, the Miata, the Elise, etc. But that's a separate conversation.
http://en.wikipedia.org/wiki/List_of_Top_Gear_test_track_Pow...
A tuned GTR easily beats the Aventador, though, for a fraction of the price.
The problem is the control systems and extra plumbing get pretty complicated. The setup in the Supra is lovingly referred to as "the rat's nest"
You can also perform an additional trick that they use in F1 - use the electric power to spin up the turbo (and harvest energy that way too). That isn't in use in road cars yet that I'm aware, but it will be I expect.
Basically my point is that it isn't about the turbo, it's about the electric motor. It might be on its own like the Tesla Model S, or it might be in a Hybrid system like the cars above, but the torque you get from an electric motor is just too good to avoid.