I was thinking recently while overhauling and replacing a broken component in a Campagnolo 10 speed Ergolever that proportionally, I don't nearly see the same amount of shiftlever failures with Shimano Ultegra or Dura-Ace as I do with Campagnolo Chorus and Record. I would say that 75% of the Campy levers that I worked on this season had broken spring carriers and or springs and the rest just needed cleaned, relubricated, and the typical replacement g-springs.
My question is, did the engineers in Vicenza design these levers to be serviceable because they were aware of the durability/longevity of the internal components with a positive PR spin of being completely rebuildable? I don't know... Maybe the loyal masses don't mind tossing $65+ not including parts per lever to their mechanic every so often. I'd be the first to say that that's a whole lot cheaper than having to replace the complete lever, but from my perspective, I'm seeing the equivalent shift controls from Shimano lasting a great deal longer under the same conditions. But hey... I'm not complaining, it's more work for me.