It is suggested that they cost too much.
http://theage.drive.com.au/green-motoring/evs-20k-too-much-survey-20120717-22716.html

Cheapest All Electric Car in Oz is about $49k, and an equivalent petrol version is roughly $25k (or even $20k).

$24k is a big price gap. Carbon emissions aside, $24k of petrol at $1.60/litre = 15,000 litres (15m3 of fuel!). At 7.5 litres per 100 km (average), that is roughly 200,000km worth of fuel.

I get bored with any car at around 120,000-150,000km of driving...

Hybrid Prius C is about $27k driveaway, but it's probably a $17k car with a $10k premium on fuel / premium for Hybrid. Assuming it is 3.0 litres per 100km better than all petrol, the result is;
- $10,000 of fuel, at $1.60 (assumed) = 6,250 litres divided by 3 litres x 100 = 208,000km before you break even. In truth, it may only be 2.5 litres/100km better off, and a 250,000km break even point.... In that ball park anyway.

Figures above exclude effective interest.