Answer:
Research usually is a cyclical process because it starts with a problem and ends with a problem.
This is bad or lessens the value of the research?
No, because there are problems that in nature are cyclical, (for example the related ones to action research).
And it also may be a good thing, solving one "problem" leads to another problem, but in the process of solving the first one we may win a lot of knowledge, and the same happens with the next one, and so on.
Two possible advantages of cyclical research are:
Knowing beforehand that the research will be cyclical, will allow us to estimate better the amount of time and money needed because we already know (more or less) where to aim.
It also may lead to a better end product, as we already know that we must focus in solving one thing and then we can focus in the next one.
Another possible advantage may be that we know that after the work, there will be a new thing to research, and it is fun, so if you are curious enough this may be a good thing (especially in scientific areas, physics, chemistry, etc).