Actually, redefining terrorism was only one of at least 2 alternatives offered. The other being , come up with a new word that refers to terrorists who kill innocents on purpose.
You have in fact pointed out that, according to Gus' definition, "unrestricted terrorism" fits the need. The problem is that the word "unrestricted" actually has no connection with innocents at all. Someone hearing the term, a layman, does not get the impression that it refers to the killing of innocents. After nine years of being intensely interested in terrorism and reading many reports and articles and books on it as a function of my job in the intelligence community with the national guard I had never heard of Gus or his definition. I don't consider myself an expert but I'm at least a fairly well-informed layman.
So we are back to the academic's code.
Blue collar guy: "I don't think that word means what you think it means."
Academic: "Sure it does. You obviously haven't read Gus Martin's paper on terrorism where he clearly gives it its new and improved meaning. That paper is freely available in the Waukeegan University Library, you filthy blue -collar sort." (spits)
(Forgive the exaggeration, I couldn't resist. )