And, in fact, scrolling the card is exactly how it works for a square Android Wear watch too. The only difference is that (with the possible exception of ugly word-wrap cases), the truncation is only vertical, not horizontal as well. Considering how much has to be truncated on a watch screen anyway, I think it is hard to make the argument that the square interface works and the circular one doesn't.
You have to scroll the text up nearly halfway just to see the beginning of the lines. That means most of the space on the screen is wasted because I can't read lines that are not right in the middle of the screen.