There is a few different reasons for an electric bike like the one at the start of the thread, as someone else pointed out, it would make a good utility bike, grocery getter etc, they can get people on bikes that may not be fit enough initially to cope with their local terrain, or have arthritis or dodgy knees as you can put more load on the motor and off your joints on bad days.
I ride all types of human powered bikes and electric assist bikes, one of my favorites is a really low powered (250 watt) electric assist bike with the motor running through the derailiers, how many lowriders do you see that can cruise at 40~50 kph and blow cars off at the lights? to achieve this requires a massive amount of pedal input and is more exhausting than riding a moutain bike up a mountain but it's a real rush and much more comfy than a road bike.