No, I wasn't being sarcastic at all (indeed, I'm hoping to have meaningful conversation, and you seemed willing to particiate). I don't think it's spurious at all.
I don't think it would be too hard do in the regs. Indeed, you and I could certainly put our heads together do it ourselves.
But focusing on that may obfuscate the real issue, in my estimation...
Now, humor me here, please.... and give this some thought: The letter author basically says e-bikes have a motor, and because they have a motor, they are by definition "self-propelled." and because they are self-proplled, they are motor vehicles. Essentially, what the letter author's logic leads one to conclude is anything with a motor must be a motor vehicle. That we can agree on, correct?
But..... if the regulation author really meant what the letter author asserts, then why didn't the regulation author simply define a "motor vehicle" as "any vehicle with a motor, period"? That would have been so easy, direct and clearly support the letter author's point. Why did the regulation author go and use the term "self-propelled"?
Standard legal interpretation requires that the words be given meaning: We can't ignore the use of the term "self-propelled" as the letter author, effectively, does. And one has to assume (legally, in the absence of contrary evidence) that the regulation author wouldn't include words within the regulation that are essentially meaningless. So, "self-propelled" has to mean something beyond "a motor" in this context. Indeed, the structural definition of "motor vehicle" as set forth the regulations precludes such an interpretation. One can't simply conlcude, as the letter author does, "if it has a motor, it's a motor vehicle." The regulation author could have done that, but, for whatever reason, chose not to.
Look, I understand folks don't like e-bikes. And folks here are certainly entitled to call me a d-bag or whatever. I'm probably all of that, to be honest. It's all good. But I'm always up for discussion!