> Loeb, though, explicitly rejects the Sagan standard—“It is not obvious to me why extraordinary claims require extraordinary evidence,” he observes—and flips its logic on its head: “Extraordinary conservatism keeps us extraordinarily ignorant.” So long as there’s a chance that 1I/2017 U1 is an alien probe, we’d be fools not to pursue the idea. “If we acknowledge that ‘Oumuamua is plausibly of extraterrestrial-technology origin,” he writes, “whole new vistas of exploration for evidence and discovery open before us.”

Uh... this isn't at all clear to me. I don't think very many people are saying it is impossible that Oumuamua was an alien construct and actively discouraging science based on the idea it could be, its just that it is a pretty big fallacy to say "we don't understand it, therefore it was aliens". Recall that the scientific community has gotten its hopes up about aliens several times in the past with scientist proffering alien explanations for "canals" on mars, pulsars, GRBs, and FRBs to name a few.

If we assume that Oumuamua is an alien construct, what "new vistas of exploration for evidence and discovery" open up that we are not already pursuing?