Why a Hybrid has been a necessity!

It is not to save the planet from some obscure gaseous exhaust. It is also no means to really reduce gasoline usage, especially in comparison to modern Diesel Engines. However, there are other benefits of hybrid drivetrains that are often ignored.

One is the introduction of continous-variable transmission (CVT), which means you don't have to switch gears and unlike automatic transmissions, you also retain the fuel efficiency of a manual transmission. However, there is even more to those CVTs, which are already in use in mobile work machines (Hydrostatic Transmission) that makes them a real choice for medium and high class cars. Modern LuK chain CVTs have the capabilities to transmit up to 300 Nm on the street which is quite a momentum. Also, they allow for perfect acceleration, since they don't have to switch between different transmission settings which are only optimal during a short phase in the acceleration curve, but rather change the transmission continously as necessity of the motor and power requirements dictate. There are several chain CVTs on the market already, early Japanese models like the Toyota Prius CVT and more sophisticated models like the LuK CVT in modern Audis.
CVTs are very complex and difficult to realize, also they are still pretty new to cars and so are produced at a premium. However, in time they will at least remove automatic transmissions in wide usage for luxury and medium range cars.

The other advantage of introducing a hybrid car to the market, is to gather experience in using electrical motors. While hybrid motors with oil fluid would also be a possibility, they haven't been found optimal for car-usage due to a number of reasons (mostly the need for a large tank and difficult maintenance in the front spaces of the car). Electrical motors have several distinctive advantages that could be used in modern luxury cars.

1. They transmit maximum Momentum even with low speeds
2. They are more quiet than combustion engines and thus are a valid options for luxury car usage, who want to be as silent as possible while retaining good performance.
3. Electric motors can assist modern ICE (Internal Combustion Engines) in accelerating and thus pushing rates even higher

The use of high-tech drivetrain gadgets in modern hybrids will bring those technologies to mass-markets thus enabling testing and picking of preferences. I doubt that hybrid cars will have a long standing success, but they will introduce some awareness for new technologies and maybe even make electrical engines acceptable or further advance research in those areas.
Especially the idea of gearless transmissions will prove to be an asset to be used in newer car models and probably is the only success story developing out of hybrid cars.

Of course, government action will help sustain a hybrid market for at least a dozen to twenty years, but not because of their effiecency and supremacy, but rather out of some lobbying effort by zealous green think tanks like Greenpeace.
Sadly this will post-pone the market selection effect for a few years, before alternative methods will arise to harness the technology developed for hybrid cars.