Americans love Congress. The approval ratings are very, very high. The ratings you cite are wrong, because they show the wrong thing: they show what people think of other peoples' Congress members. American voters are very happy with their Congresspeople; that's why they keep re-electing them. They just don't like everyone else's Congress picks (esp. ones in the "other" party).
I don't know if Americans "love" congress, as much as we are just ignorant to who are what congress is. See someone from the other side, hate em, see familiar name on the ballot, vote for em.