Actually we don't know how many well trained biologists and scientists think this valuable or not. You are concluding something not evidence. You first state a fact, that the DNR has well trained biologists and scientists; but you have offered no proof of the conclusion as to how many do or do not feel it is worth the effort. If you do have evidence you can present it.
As for my opinion, I think it is worth the effort IF the survey is designed correctly and they get a result that has good correlation with the actual beliefs of the target group. I think the published results should list not only what percent gave each answer but also a probability analysis as to the confidence level in each answer.
Secondly, I think epidemic (def - widespread, excessive prevalence) is way overstating it. Trout anglers are increasing not decreasing so how can those leaving be an epidemic? If there is an epidemic it is those beginning to trout fish not those leaving. If there be an epidemic it is in the use of hyperbole.
I leave it to those who read our contrasting views to decide who is more correct.