lol, I don't know a thing about Johnson. He hasn't raised much… awareness.
Did they really chain themselves to cars? There were news reports of that, but I didn't see any photos. As you suggest, protesting is fine, and perhaps in cases like this one, necessary. But take it too far, and there'll be a backlash.
Even in '68, I wasn't much of an activist. I did contribute to Gene McCarthy's campaign, though I was too young to vote. (The voting age was 21 then.) I DID to to a Spiro Agnew rally, I think in Cambridge, and heckled him.
Civic duty.