That is such bullshit – and I'd offer your own excellent book Rip It Up And Start Again as evidence as to why.
That seems an uncontroversial observation to me - PiL and Joydiv were easily the most prominent and influential groups. Joy Div were widely imitated, PiL less so cos actually quite hard to copy, but Johnny L's and Wobble's line of patter had a big effect.
Who else was more influential or seen as pointing to a right path?
The Fall were highly regarded, but their influence didn't really come through until the mid-Eighties with all the shambling type groups.
Talking Heads? The Banshees, i guess ultimately did spawn a genre (a mixed achievement)
Same goes for Throbbing Gristle - i don't think they were that widely listened to but nearly everyone who did listen to them seemed to put out music - a mixed blessing, judging by the tapes that have been diligently archived on dozens of industrial blogs.