In my experience, there are four types of researchers:
a) the full-time scientists that look at stuttering by opportunity and chance
b) the scientists that focus their academic career on stuttering but do not treat but teach.
c) the generalists that focus on all aspects of stuttering from research, teaching, and treatment.
d) the practitioners who focus on treatment and teaching but do research part-time.
Type a are mostly geneticists and neuroscientists. They are in my view the best scientists for experiments. They now relatively little about stuttering as a disorder, and live in their experimental paradigm. They just happen to fall on stuttering. Without bias, they just look at stuttering. They are mostly funded by general research councils, and publish mostly in non-stuttering focused journals. I trust them most in terms of experimental results.
Type b knows a lot about stuttering and are professional scientists, and direct their research according to what they perceive as an important experimental question. They say: I have a theory and I want to test it, whereas Type a says I have an experimental method and I want to use it. They publish in both stuttering and non-stuttering journals. They also get their funding from research councils but they might rely more on money pools with a focus on speech and language or communication sciences. Such research resources are often dominated by some professors. Especially junior type b are relatively sensitive as not to offend such an important person who might be editor of a stuttering-related journal or a powerful member of a research council. This is especially true in the UK, and also to some degree in the US and Australia. At least four have told me that they try not to provoke or openly criticise work by a big name, because they are scared of having a paper rejected or getting no funding. Actually, they like me because I say what they do not want to say out of political reasons! So view my blog also as the voices of some in the research community!
Type c is a bit of a generalist. They do teaching, treatment, and research. They are quite focused on stuttering journals, and are at all the conferences. They mostly publish in stuttering journals. In general, they are not full-time and not very good scientists, but are good all-rounders.
Type d are practitioners first. They treat patients, but are too energetic and intelligent to just do their job and go home at 5 o'clock. They are closely connected to the stuttering associations. They are very much focused on treatment, and do research in the area. It is often non-funded research, small pools of money or funded by private money.
In any research team there might a bit mixture of researchers.
I forgot Type e)
e) They stutter, generally have a good science background, and follow research in stuttering. They do not do any experimental work nor treatment nor teaching. They do meta-analysis of research and try to understand what stuttering is about. They do it all for free. Some even write blogs! :-)