I consider a strawman argument to be an intentionally flawed extension of someone else's argument. I don't do that. My extensions may be flawed due to a misunderstanding, but that style also forces a focus on such misunderstandings. I think it works well if people are willing to listen to each others arguments and adjust to a better understanding of anothers opinion. Unfortunately, many people are really dug in and my technique may effectively have all the faults you sight. Perhaps I should limit the technique to those few willing to change their minds on an issue and those issues that are not emotionally charged.

I do however strongly disagree with your statement that this is an invalid technique. It is a basic part of science to test a theory by expanding its application. In addition, if you state a principle as a general one and I show through another similar example that it is not, that is a valid form of proof your claim was false.

Regards,
Mark