ALL the Tesla drivers are taking the bus because their $50,000+ "car of the future" can't run in the cold. Looks like consumers will still be buying a vehicle with an internal combustion engine, not one with unreliable batteries.
Granola power doesn't work very well when you're outside California, it seems...
You only need a block heater if you're turning the engine off for 8+ hours (depends on temperature and wind). Otherwise, the engine will run and stay running until the fuel runs out, which at idle is relatively efficient. Internal combustion engines heat themselves naturally as a byproduct of generating power, instead of requiring an additional draw of resources. This waste heat can be used to heat the cabin and passengers.
Electric cars need a constant heat source to keep the passengers warm, as well as to keep the batteries warm enough to keep the motors running. At cold temps it is incredibly inefficient in terms of how much battery power is used to do these two tasks, in addition to powering the vehicle as it accelerates.