UTC and TAI are already over 30 seconds apart. So not using a negative leap second to keep them aligned isn't really a valid argument. On a geological scale, Earth's rotation is slowing down, but on a decade scale, it's still pretty chaotic. We could just as easily be having the reverse conversation. When we need a negative leap second, we may need a few in a row. So just waiting for a positive one to cancel them out doesn't really work. Using the logic of it will all eventually be a wash and we shouldn't use them at all is kind of the argument the article is making.