I've owned an electric kettle for over a decade.
They aren't ubiquitous here, but go into any Walmart or Target and you'll find them there.
The real reason they aren't ubiquitous in America is the majority of Americans aren't daily tea drinkers and most (notice pedants I said most and not all) American coffee drinker use drip coffee machines or Keurigs instead of a French press, so for most Americans there simply isn't a regularly enough need for hot water so as to justify an electric kettle.
That's it. That's the whole reason.