Good point in that article, Dan
... and one I was thinking about... namely, that if the speed of anything was infinite, it would not exist. It would go from wherever it might have any effect on anything to infinitely far away in no time at all, and therefore not have any further effect on anything "here" (wherever the observer might be). Since it left so quickly, it couldn't have any effect while it was "here" either, and since it doesn't have any effect at any time, it doesn't exist.