I agree there is a need to sell the need, and this page doesn't do a good job of doing that because while a looping animation is good for showing the animation, as you say, it isn't a good idea.

I can see animations like these working for when a user interacts with something, as an alternative to just highlighting or doing a material style ripple. The problem is that most of the time I'd want that, I'd also want to transition between two states, which—unless I'm missing it—isn't something this offers.