You're still here?  I thought you wanted to "part ways."  

To the extent that I "poo-poo the significance of the Loud Biker issue," it's because IT IS NOT A PROBLEM IN PORT ANGELES.

For all I know, Houston, and Armpit, Arkansas, too, may be living hells of unbearable biker noise.  So your crusade may make perfect sense in the places you know.

But here, where most PDN readers live, and where this incident took place, MOTORCYCLE NOISE IS NOT A PROBLEM.    

I must say, though, even if it were the worst problem facing us  --  which, I repeat, IT IS NOT  -- that would still be no justification for a man of mature years going all foul-mouthed and violent on a couple of young women who just wanted to know what his sign was about.  

I'll re-use your own quote:  “The 17-year-old and her adult friend … walked up to James Naval and asked him what his sign meant..."  Around here, that's just being civil  --  and not a justification for assaulting someone.