I had considered starting apost on this very topic, but I stpped myself, for the reasons you mentioned amongest others.
Yes it was a great technical achievment, flying at 60ft with nothing but a couple of spotlights to tell them they were at 60ft, a bouncing bomb.
Though do we really glorify war when we mark these days? Or is it a way of commerating those who fought for our freedoms? Perhaps in this case it is because it's the 70th anniverdsary of the raid it is getting attention, will the 71st anniversary garner as much attention?
Think about it the 68th Anniversarry of VE day passed by just over a week ago, and I don't recall seeing a thread about it. In many respects perhaps the one day in the UK outside of Remembrance Day and/or Remberance Sunday that perhaps gets a bit of attention would be the 15th September Battle of Britain Day.
I think it is just a case of it being a big number. And it isn't just war. They're celebrating 50 years of Dr Who this year, just as they celebrated 50 years of Bond in 2012. Like you say, no one really cares about the 49th or the 51st.
Also have to remember that aim of the raid was to shorten the war. Unfortunately history has shown it didn't. Had they breached the 3rd dam (The Sorpe?) I think would have been very different.
Well this still seems to be up for debate. Dan Snow's written a very interesting article here
and I think he talks a lot of sense. Yes the Germans rebuilt the dams very quickly, but they had to retask an awful lot of resourses from other areas to do it, notably diverting men and material from the defence of France. And like he says, the propaganda impact can't be underestimated.
If they had breached the third dam though, well who knows...