Ska is ska. Whether YOUR OPINION'S like it or not.
Upbeat timing/chords, off beats, typically horns, random quirkiness/satircal-ish comedy, shitload of percussion (IMhumbleO) lol, and mainfested positivity! That is basically ska.
Not limited to a specific era of time. BECAUSE, good sir, then EVERY damn genre of music would ACTUALLY be dead. lol
Unlike punk or ska. Which are still very much alive..
And besides didn't the age of ska that you mentioned result from the American clash of rock w/ Jamaican reggae?
Like the Mento and Calypso styles coming from Africa and South America to help form reggae and the genres of Jamaica..
Now, i shall rip some Propagandhi. One of the last true fucking punk bands.. lol and in their own words are "Anti-fascist, Gay-positive, animal friendly, & pro-feminist."