F1 is just one type of what is know as "road course" racing in the US. There are plenty of other categories, including off road.
Having driven Nurburgring as well as having spent days training at well known US race courses I can tell you that turning left all day feels just like being on a busy freeway. Take away the crashes and nobody would care.
A road course requires skills not found in the "let's all turn left for 200 laps" courses. Not even close.
The other aspect of road courses is that they require a very different level of concentration and physical endurance. Hard to understand this without spending a few hours driving a race car on a road course.
OK. Yes, I know NASCAR goes to road courses a couple of times a year. Yet, NASCAR, for the most part, is oval-turn-left racing.