My Grandfather told me that at one of hos first jobs the shop owner insisted that the balance staff get replaced on all the watches that came in for service, regardless. And they charged for it! This is pretty extreme, not to mention unscrupulous. He didn't work at that place very long.
But anyway, I suppose one could call it a design flaw. Then again the top speed of a Model T is only about 40 mph too. These watches were designed and built using the best technology of their time.