The point is that the mechanism is does NOT work similarly to how an electric motor works, nor does it look similar to one. They are just not the same thing.
That appears to be the ID argument being made by some people, especially because they are often unwilling to explain it as an analogy or acknowledge where the analogy fails. See, for example, this thread. @bjmiller was building the rhetorical impression that the flagellum = motor, and when asked to clarify the distinction, there is no response. I don’t want to over-interpret a single example of silence, but this is a pattern that takes place over and over. If he is not equivocating the two, he could clear it up very quickly by explaining the dozens of disanalogies between rotary motors and flagellum. I’m doubtful he even knows what the differences are, so I’m not accusing him of dishonesty here. Rather this is just a case where shallow understanding of biology might be showing.
The “electric” part, however, does not even work well as an analogy beyond the most surface of levels. Electric motors and flagellum both harness charge differences to produce physical movement “somehow”, and that is about where the similarities end. The way they harness these charge differences could not be more different.
Great examples of differences, though there may be an “electrical” current involved, not of electrons, but of protons. Depending on how we define electrical, this could count as a current. Of course, how this current is made use of is totally different than in a human designed rotary motor.