You're absolutely correct. What's puzzling is why people think a windfall profits tax would be beneficial to anyone other than the government.
I would love the major oil companies do an ad campaign tell people their profits versus the taxes they are already paying. Show people their profit margins versus that of the likes of Google, IBM or Apple. The American public needs to have their eyes opened with a bit of reality.
The windfall profits tax as proposed is indeed odd and that it would get so much support is not good news.