How would potential research advisors view someone entering graduate school because of interest in particular "real-world" problems, with the ultimate hope of leaving or changing fields if these particular issues are resolved?
I can come up with a few examples. Perhaps someone is very passionate about a particular disease for personal or family reasons, and 15-20 years later therapies have progressed to the extent that they feel the problem no longer needs their attention. Maybe someone is passionate about climate change, environmental protection or missile defense because of the challenges of their hometown, and 20 years later political circumstances change (e.g., in the last case, the Cold War ends) such that they no longer feel these issues threaten their communities.
This model of thinking about one's career, "If society is successful the problem will be solved and we can all quit our job" contrasts the life-long academic model. At the same time, I feel that's how many people are motivated to enter research, not from the perspective of "I'm interested in X technology" but "I want to help solve Y problem".
My concern is, if I interview with potential future advisors with this kind of story, even if the political problem I'm focused on has a long, 1-2 decades timeline for resolution, a future advisor might find this kind of attitude "disloyal" to a field. When advisors ask about my interests, I feel that they're looking for a response that describes intrinsic academic interest in a topic, "I think X is really interesting", rather than a framing of research as "I'm concerned about Y political problem that you might not necessarily care about or may even disagree with, it's unlikely to go away in a 10 year time-frame, and I think getting a PhD in Z is the best way for me help my community in working through this problem". Especially for a pure-academic, "I'm primarily motivated by recent, specific political circumstances" may not sound very dedicated coming from a student entering a new field for them, even if all signs point to this problem staying around for decades. And for certain issues, like defense/ security, advisors may object to training students with this motivation because of their ethical views.
What concerns would such an advisor have, and how can I respond to them?
I'm in a technical field, for reference, but am interested in answers oriented towards humanities-oriented fields as well.