Yea, some people are disappointed; some of the more interesting and exciting moments in physics are when we find out we're wrong, but not always. E.g. I will never forget the time and place I heard about the preliminary detection of primordial B-modes by BICEP (which turned out to be dust contamination) -- that was a predicted detection from canonical inflation models, as the Higgs was a standard prediction from the standard model (also a pretty exciting moment).
Not seeing something when we "expect" to not see anything (from the perspective of certain models) might be more boring, but it's definitely not a "waste" (again speaking purely from a physicist's standpoint).
We know the standard model is incomplete, but where and how are not well known. Not seeing evidence for new physics rules out certain models, and places upper/lower limits on others. It's progress either way.
Some do I'm sure. However if we see something unexpected and it turns out to be true that means our ideas of physics are fundamentally wrong. While it is long term good to correct our understanding, in the mean time a lot of the real world depends on us being right, and so until we correct the theory who knows what will work. I'd hate to find our margin of safety on nuclear bombs was too small and it is only luck that they haven't all blown up in their silos over the years.
The quantum mechanics approach is to get a good idea about what happens for everything under a certain energy level.
They keep building bigger machines to fill out the parts that don't have a definition yet.
Anything that specifies what happens at the next band of energy levels is a success, whether it yields new particles, or rules them out at that energy level.
There's some destination of approaching the most energy dense states like describing the mechanics that were active during the big bang period
Hossenfelder has a lot of... unique takes in the physics world, I don't think she should be used as a general barometer of the field.