In general, American roads are a lot bigger and straighter than European roads, meaning in terms of consumer preference, horsepower matters more in the former, and being nimble matters more in the latter.
I agree with you that not every car needs to have a sub-6 second 0-60 time. A 9.8 second 0-60 of the Kicks is considerably faster than, say, a Fiat Panda.
In America torque matters more than horsepower and torque is what keeps you running at high speeds. In Europe horse power matters more as that is what accelerates you from a stop. What sells (and is marketed) in each country is different of course.
No, horsepower to torque*rpm (and some other factors) is what you get at high RPMs which you normally accelerate from a stop. Once you are up to speed your transmission switches to low RPM where you get less horsepower, but better fuel efficiency.
I agree with you that not every car needs to have a sub-6 second 0-60 time. A 9.8 second 0-60 of the Kicks is considerably faster than, say, a Fiat Panda.