America is inbred, it doesn't quite have the worldwide pedigree of motorsport like F1. Indycars and Nascar don't translate well outside of the States and Canada thus not given the coverage it perhaps deserves.
I lived in the USA for 3 years - the reputation americans have in other countries is not very fair. However, they do package their sports very differently, which doesn't translate well to europe. But don't confuse the packaging with the sport itself.
I spent a happy year a few years back, following Indy, and it was very good. This year I have also watched a few - and it was pretty good too. But the american coverage is really not to my taste.
I think Indy would be a lot more popular in Europe, if it was covered like the BBC cover F1 - and with the picture quality we get in F1 (even tho not HD). I am sure the same is true in reverse, with F1 - but its harder to create the show that they may want, to really get into F1 in the USA.
Still, they have some nice things in Indy coverage - the continuous banner over the top, so you always know how people are doing is particularly good (albeit in cheesy graphics).
They have more overtaking than F1 - at least in the ones I have seen recently.
The strategy also applies - they have two types of tyres etc - but their coverage really doesn't follow it.
If the BBC covered Indy, I bet it would be much more highly regarded, at least in the UK.