First of all, one has to distinguish between indirect and direct predictions theories. For example concerning theories describing physics at very high energy regimes, such as energy scales where quantum gravity effects are expected to kick in, it is clear to everybody that these high energy scales are with the current technologies not DIRECTLY accessible at the moment. Nevertheless, people working on the phenomenology of these theories are able to extract INDIRECT predictions and hints, that can be observed or excluded at the "low" energy scale that are accessible at the LHC, from cosmological observations, direct searches etc ...
So claiming that physics is not falsifiable just because the regime it is intended to work is not directly accessible is simply wrong.
Second, with the advanced theories we have today in fundamental physics, the aim is no longer to confirm them by a single observation as it was possible in the past, but rather (more or less direct) hints are accumulated that speak in their favor and increase the trust we have in them. However, for many theories it is still possible to falsify them by a single observation of theoretical consistency considerations.
Just recently, there has appeared an interesting work of science philosophers who succeeded in proving by probability theory that the so called "No alternative argument" can legitimately increase the trust in a theory describing the physics of a regime that is not directly experimentally accessible, just because nobody is able to come up with a viable alternative.
So it is certainly not justified to say that doing physics valid at regimes that are not directly accessible at present is a waste of resources and money etc. Young people interested in fundamental physics questions should not be discouraged by such negative statements in popular media and magazines ( by people who are often not experts in these fields) from following these interests and taking a corresponding path in their career. As too often since quite some time ago, the Scientific American is reporting about fundamental physics in a way to pessimistic and negative way which is orthogonal to what physicists actually working in these fields think. To get reliable information about such topics and questions, one better does not rely on the Scientific American these days. A better source of honest and well explained information about particle physics and other fundamental physics topics is Prof. Matt Strassler's site for example.