Actually, the previous versions of FCP 7 did stop working in one very important way; a multi-seat system built around FCP 7 could no longer be expanded legally.

Actually, the previous versions of FCP 7 did stop working in one very important way; a multi-seat system built around FCP 7 could no longer be expanded legally. Sure, you could finish what you were doing, provided you needed no additional resources. But you couldn't switch to FCP X without cutting yourself off from audio post, effects pipelines, and so on. If you wanted to grow your operation in the "who knows when support for interchange will appear" window, you'd have to abandon FCP altogether, and re-invest in Avid or Adobe. That's the epitome of a broken product.