Why are Baptists still discussing their origins?

Why are Baptists still discussing their origins? For the last hundred plus years, major Baptist seminaries, though varying on minor details, have fairly consistently taught that Baptists originated in England in the early 1600s. Why does anyone think otherwise? I can think of a few possible reasons why we are still discussing the when of Baptist origins.

The theological/historical divide. There is a great divide at the far ends of the spectrum. For some Baptists, their understanding of certain verses of the Bible require a perpetuity of the New Testament faith throughout the centuries. For others who think the Baptists are no more the New Testament church than the Methodists or Presbyterians, there is no theological motive to question the prevailing notion of Baptist origins. Also, the nature of historical argument is that of research, discovery and interpretation. Historical argument is always subject to revision; it is written by fallible humans. For even those not driven by theological concerns, there will always be the changing winds of reinterpretation of the evidence. Historians enjoy being the discovers of new things. Or as Samuel Butler said about historians altering the past...

Barring major new discoveries of original documents, there will probably always be, from the historical standpoint, a seeing through the glass darkly. Both historians and non-historians notice this, as a writer in an internet forum observed, "It seems to me that Baptist denomination doesn't have a very clean beginning like our Lutheran friends or our Wesleyan friends who can point to a founder. We can just point to groups of founders and churches." Even historians who hold the 16th or 17th century origin of Baptists have pointed this out. In Baptist Origins Revisited: a Study of the Dual Influence of English Separatism and Dutch Mennonite Theology upon Seventeenth-century English Baptists (Doctor’s Dissertation, New Orleans Baptist Theological Seminary, 2002, p. 1) Matthew D. Wohlfarth noted, "As opposed to Lutherans, Anglicans, and most other distinctive expressions of Protestantism, the emergence of Baptists is shrouded within a variety of influences and movements." William H. Brackney, in The Baptists, writes: "There will never be an answer which satisfies all or even most Baptists since there is no date, no place, and no person to whom all can look with complete confidence as the locus classicus of the movement." (p. xvii)

Finally, there is the lack of agreement on Baptist identity -- "What is a Baptist?" If we cannot define what a Baptist is, how will we know when we see one in an historical record? Within the varying camps of Baptist origins, there are varying ideas of what constitutes Baptist belief and a Baptist church.