I don't see it. If we already know the right answer (say, this insulin-producing bacterium is a product of human design), are you really claiming that science is incapable of detecting that? I seriously doubt it. But if so, how is it possible for science to make any authoritative statement about origins?
Even worse, without knowing the history of an object, you don't know what steps were required to produce it, and without knowing the steps, you cannot do a meaningful probability calculation.
That's an unnecessary constraint that essentially calls for scientists to ignore any knowledge of how things (in general) get made. We need not know the history or manufacturing processes used to create the artifacts found by archaeologists, and yet we are still somehow able to identify things as "made." How? Because we can often recognize the signature of "made things." Moreover, even if we're uncertain about the origin of an object, we can try to discern it by looking for known characteristics of "made things." And thus an archaeologist can label an unremarkable chunk of stone to be "a primitive tool."
No one in science claims that any complex structure poofed into existence in one step, and no one in ID has found a structure that isn't comprised of simpler, functional structures.
An airplane meets this criterion. Are you saying that a "design hypothesis" for the origin of that airplane would be wrong, simply because the airplane is comprised of "simpler, functional structures?"
I am saying that ID is not a design hypothesis until it makes specific, testable statements about the history of the objects or structures is claims are designed. We know that airplanes are designed because we know their history. There is no mathematical or objective method for deciding that an object has a specific history.
What you can do is demonstrate that a specific conjectured history is possible in that it follows all known physical laws.
What ID lacks is a proposed mechanism for the occurrence of the objects under its purview, and a proposed history for those objects. It needs to propose some characteristics of the designer, some abilities and limitations that can be put to the test.
So far, ID has asserted that certain structures could not have arisen by incremental steps. Each of the structures proposed has failed that test. Eyes, blood clotting, flagella, all have simpler implementations and examples of functional substructures.
You cannot calculate the probability of a structure arising naturally unless you know each step in its history, and whether each step is likely to occur naturally.
So if ID wishes to make some kind of Drake equation, calculation the probability of living things arising naturally, it needs to know the actual history of things, so each element can be properly entered into the equation.