Presupposition might not be a wonderful thing, but self-recognition of presupposition certainly is. By this I mean that scholars who write with a self-awareness of their own approach to the text but set it within its proper perspective (not just the false-humility under the pretense of complete objectivity) seem to have a more well-rounded exegesis. It is fine to presuppose and to come with some conclusions already made, but to complete a study (especially research) these need to be open for reconsideration. My present grievance is when conclusions are drawn too early in the process of biblical interpretation.
I'm presently working through a thesis for my own doctoral research: Guy D. Nave, The Role and Function of Repentance in Luke-Acts (Atlanta: SBL, 2002). Admittedly, I don't know much about Nave, so there might be aspects here that are more apparent to others. I am in the beginning stages of reading through his study, his proposed methodology and such, when I came across some presupposition that seems oddly out of place.
The author states:
Finally, not only is everything that has been accomplished among the author and his reader in accordance with God's divine plan, but God's plan has predestined these events to take place. In Luke-Acts the plan of God was predetermined by God, and the plan itself has predetermined the events which have taken place (p. 17).
This point is presented quite early in regards to the thesis and seems to shut the door on some other legitimate interpretation before such passages are investigated. Such an assertion is clearly made to *predetermine* the author's conclusion at the outset of his thesis. And it is done unnecessarily at this point of Nave's work, when he has made some wonderful comments regarding the nature of narrative and authorial intent. The fact that there is a plan does not necessitate a comprehensive design of every action - hence, God's exact plan cannot be that things do not work according to his exact plan. Rather, the notion of a plan among free creatures captures the sentiment much better (as does other, more thoughtful deterministic views).
In the interest of full disclosure, my presupposition is that of a free-will theist. However, I do not necessarily agree/disagree with an author on this basis; I have found that many scholars from the Reformed camp have made wonderful contributions to the discussion, when they have done so properly.