That is the case sometimes. I think that is the complaint that T. aquaticus has, for example. I don’t reject your point. However…
I lost count of the number of times that TE evangelicals on BioLogos or in ASA forums said things like (I paraphrase): “Science deals with the factual side of nature, whereas questions of purpose, meaning, and value belong to theology or philosophy, so design inferences can’t be scientific, but only philosophical or theological stances taken toward nature.” If we were on BioLogos, five years ago, I could point to examples of this probably at least once a week; it was a kind of standard response TE response to ID claims. Another version of it was: "We can see design in nature, but only through “the eyes of faith” " – which meant that design was not an objective property of any natural object or system, observable or measurable with devices (like mass, crystalline structure, electrostatic charge, etc.), but only a subjective gloss on the phenomena, which an atheist would not apply, but which a Christian would. Scientists, when speaking as scientists, were not allowed to speak about “design” in physical, chemical, or biological systems or entities. They could do so only when they took off their scientist’s hat, and said that they were speaking just as a Christian, or just as a person, etc.
Do you see the point? The point was not specifically about methods of testing, etc. A “demarcation criterion” (or more than one) was being applied, to ensure that all design inferences were necessarily outside of science. That is very different from saying that so far design inferences have not provided adequate means for testing themselves. It is one thing to say that so far design arguments have not met the standards required, and other to say that in principle design arguments never could meet the standards, due to a strict and inflexible demarcation between science and faith, or science and theology, or whatever.
The TE argument to which I’m referring is that it’s wrong ever to look for evidence in design in the context of science, that all of ID is based on a huge category error. And Gould-like notions are called in by some TEs to justify this rejection. I’m not blaming Gould for that.
Of course, there is another wrinkle in this: TEs are not consistent on this point. Many of them will say that design arguments, in principle, don’t belong to science, but to theology or philosophy, which, one would think, would cause them to stop responding to ID arguments. But in fact, they respond to ID arguments all the time. They call them “bad science,” and try to show the scientific errors, as if, if those errors were not present, ID could be “good science.” But it’s inconsistent to say that ID arguments are “bad science” when one believes that in principle they aren’t science at all, and couldn’t ever be. And it’s also a waste of time; if ID arguments couldn’t possibly be scientific, then they couldn’t be either good or bad science, so why invest even a minute responding to them at all? So there is very muddy thinking when some TE leaders take both lines against ID simultaneously.
Anyhow, it is this line of argument among TE/EC leaders that rankles me, not the line of argument you are talking about.