Just because something wasn't _designed_ to be reliable doesn't mean that it _isn't reliable_. They're two related but separate aspects. What that article examined was the reliability at that point in time of the network between those points. And based upon the numbers, it looks pretty darn good.
As engineers and designers, we tend to overbuild systems; insisting on "reliability" as a holy grail when the application doesn't necessarily demand it.
UDP has a lot of advantages when it comes to being lightweight and easy to throw out there. If we can let go of our insistence on unspecified …