The halo effect is real. If you’re part of a slow moving field, people implicitly or explicitly assume it’s your fault (regardless of whether it is.) Which means that clearly you are bad at picking fields at the very least, and an incompetent stupid person at the worst.
People like funding winners. Regardless of why this is the case, the phenomena incentivizes people to paint their field in the winner category, not the loser category regardless of the reality.
Smart people like going where the action is. So if people see that your field is stuck, the talented (esp. young) people will go elsewhere. This effect makes it so that even if a field isn’t stuck, being perceived as stuck tends to make that become the case. If you want a continued influx of talented people, make sure people don’t think your field is stuck.^3
This effect is especially pernicious in academia because of its dependence on grad students. Graduate students are the labor in academic science and engineering. While it is an uphill battle to switch fields anywhere, the dynamic in academia where a grad student’s one-off choice of a field (and lab) when they’re applying to and starting grad school makes the window to convince people about a field particularly small.
Contrast to being in a field that seems like a rocket ship. Concretely I’ll talk about AI, but it’s happened to Nanotech, string theory, biosynthesis, etc. Laypeople are interested in your work (almost regardless of quality) just because it’s associated with the new hotness. The halo effect comes out in full force and you’re asked to opine on everything from ethics to the future of X regardless of what your actual research is.
^1: This note focuses primarily on research fields, but this same phenomena applies to other fields as well.
^2: A field being ‘stuck’ is obviously a Nebulous concept. Trying to pin it down by saying something like ‘the field isn’t making as much progress as it once did or as people expect it should’ doesn’t really help.
^3: Yes, someone might see a stuck field as a challenge, but the number of these people is tiny compared to the number of people who would divert away from a stuck field.