Well, where to start... I do think that the foundations of physics are and have been in a deep state of crisis for quite some time now, but I do not know how far this has infested the rest of the field. My expertise is restricted to the former. The author refers to Thomas Kuhn in the article, which - as I see it - is a very appropriate way to look at it. Here's the relevant passage from page 4 of the article, which sums up Kuhn's ideas quite nicely:
Gian Francesco Giudice said:
In his famous essay "The Structure of Scientific Revolutions" [10], the science historian Thomas Kuhn identifies a pattern in the development of scientific theories that is common to all revolutions in science. By freely reinterpreting (and simplifying) Kuhn’s structure, I can distinguish three phases in the process. The phase of discovery is when new conceptual breakthroughs and experimental results lead to the emergence of a new theory that departs from old paradigms. This is followed by a phase of consolidation, in which the theory is understood at a much deeper level and confirmed by precise measurements. This process has the effect of transforming the new theory into the established paradigm of normal science. Inescapably, this is superseded by a phase of crisis, in which the normal theory can no longer address new conceptual questions or explain experimental data. This phase is characterised by the search for new paradigms and marked by periods of confusion and frustration. Finally a paradigm shift occurs, which results in a radical departure from normal science, thus activating a new phase of discovery and marking the beginning of a new cycle.
What I do not like about this description by the author is that it makes it seem like the crisis resolves itself. But on the contrary, Kuhn described that without a successful revolution the crisis persists, worsens and deepens. By a "successful revolution" it is meant that one of the groups competing for a new paradigm (which always exist) convincingly resolves the fundamental conflicts in the field (not just the ones concerning the subject) and becomes dominant.
Now, why do I think the foundations of physics (not just particle physics) currently are in such a state of crisis?
For almost a century now we have had two major schools of thought dominating the field of fundamental physics, namely the relativists and the quantum theorists. It is not a secret that these two way of viewing the physical world have not been fully reconciled with each other, even though steps in the direction have been done with quantum field theory and the like. What we see today is various schools competing to become the dominant narrative for a so called theory of "quantum gravity", the major ones (by my judgements) being Loop Quantum Gravity, String Theory, Quantum Field Theory on Curved Spacetimes (coming from the Haag/Kastner School) and Causal Dynamical Triangulation. Of course, we already have dominant narratives within the two major schools, that is the Standard Model of Particle Physics among the quantum theorists and the General Theory of Relativity (still) among the relativists. This is where most "quantum gravity" schools start from, or at least this is what they are aiming for. Of course, most regular visitors of this subforum know this, but it is worthy to state the situation explicitly.
Now, despite the fact that String Theory appears to have become dominant, it really hasn't solved any of the fundamental problems in the field. Yes, one can argue a lot on what those are and this is an important discussion to have, but at the end of the day at least some of them have to be resolved. String theory (or any other of the schools) did not do this, but instead it created loads of new ones (e.g. missing dimensions, landscape problem) and - much like the other schools of "quantum gravity" - is becoming increasingly ad hoc and abstract. This is precisely what Kuhn described as symptoms of the crisis. That is, I argue that the rise of String Theory is a symptom of the crisis, not a sign of its solution. Taking "It's the only game in town" as an argument in favor of String Theory is but another indicator of how desperate the situation has become.
As for the origins of crisis, I think there are three main categories of problems (as far as I remember, Kuhn also argued along those lines): Those that concern the subject, those that concern the way the science is done (institutional) and methodological issues.
the subject: This is basically a lack of ideas and good strategy to approach the problems of the field. In my opinion, better training, more space for critical thinking and more support for young researchers with fresh ideas would solve this problem.
institutional: Todays universities are not primarily laid out to train the next generation of researchers, but to "prepare" people for their jobs outside of academia (at least that is the official narrative). They are very locked-in, elitist, hierarchical-structured institutions, which do not cherish free thought, but technical problem solving (as long as it agrees with the textbook) and obedience. Most universities and much of the research without direct prospects of leading to a sell-able product are chronically under-funded. When it comes to fundamental research, which by definition is the basis for all other research, the most money is not going to the best researchers with the brightest/most sound ideas, but to those doing the best marketing. Moreover, jobs are not given on the basis of academic merit, but on the basis of publication counts (content does not matter as long as people jump onto the bandwagon), on how well one can attract funding and, of course, whether one knows the right people. IMHO, it is in this light that the "success" of String Theory has to be viewed (see, e.g. the books by Woit and Smolin).
methodological: If you are a theorist or mathematician, you know how hand-waving some of the arguments in theoretical physics are. Rigorous proof and careful formulation of mathematical problems is something for pigheads, open philosophy is shunned at, while bad, hidden philosophy runs the game. The emphasis is not put on understanding, but on getting quick results - no matter how they were obtained.
Yes, to a certain degree this is my opinion, but it is also based on personal research and a lot of hard-won experience with the academic sector. It is sometimes difficult to separate the above problems, but I think that all three need to be approached in order for the subject to have any future.
(Actually, it would be massive progress in string phenomenology, even to have a "standard model vacuum" which gave calculable predictions for all SM parameters that were of the correct order of magnitude.)
