I disagree. While such speculation obviously won't produce immediately useful data, where would we be today if noone had ever speculated about something which at the time could not be falsified? Case in point: the initial speculation on the existence of germs, which at the time was unfalsifiable.
(Edit: adding refs)
https://en.wikipedia.org/wiki/Germ_theory_of_disease
From the arcticle: "By the early nineteenth century, smallpox vaccination was commonplace in Europe, though doctors were unaware of how it worked or how to extend the principle to other diseases."
So doctors were saving lives even though they had no idea exactly how or why it worked. They could neither prove nor disprove why it seemed to work, it simply did. The fact that it was unfalsifiable had nothing to do with the truth of the matter - it still saved lives.