“Violent yet rare events, such as a supernova explosion or the collision of two black holes, should make the biggest and most detectable waves.”
Unless your presuppositions regarding such objects/events are completely false...
True enough, if you accept an unproven hypothesis, it’s tough to explain when things don’t work out.
Unfortunately the article seems to miss that obvious point. The most important aspect of the failure to detect gravity waves is that is brings into at least some doubt the validity of Einstein's General Theory of Relativity. That is a very big deal and, IMHO, a source of great embarrassment to the physics community.
Plenty of hard evidence for both.