It is my opinion that it is correct to remember this particular protest BECAUSE it involved priests (and also nuns I believe). Forty years ago priests, nuns, ministers et cetera were held in higher regard in their community than now and more often than not one could pick them out in a crowd because they wore there habits or clerical collars. For them to step forward as they did was 'big' at that time.
We still remember the Boston Tea Party from the American Revolution era over tea being taxed. This protest was over the draft and the war that consumed fifty-thousand American lives and untold thousands more on the other side.
I don't think it is being commemorated due to the fact that they were religious people. It is being remembered because it is seen as a turning point of popular opinion against the war. Draft card burning was a popular thing at the time, so was burning bras for women at their demonstrations.
You yourself, HoCo guy, point out that laws were broken and time was served. Rosa Parks and Martin Luther King among others went to jail for protesting what they believed in and we remember them annually. Pedophile priests are not the only pedophiles around and if they're caught and convicted, time gets served.