The guy that was the head mechanic (and now owner) of the Schwinn bike shop I worked at said that they couldn't get enough Schwinn's in the early years of the 70's; that for a long time, the shop had a single Schwinn 10 speed so that they could show people what was available from the company. He said they looked and bought anything they could find... everything flew out of the front of the store. So, it's understandable that Schwinn would think that their formula was fine for the American market. It's been noted in histories written about the company that the management was certain (to the point of arrogance) that they had the bike market of the US figured out at the time. It was probably hard to "keep your head in the game" when your desperately working to keep up with demand and you just went through the best years of sales that you've ever experienced. Maybe never finding a way to shake their image of the seventies, or not really seeing that it needed to shaken off, did start downhill portion of their ride as a company. Sometimes, especially when the wind is at your back, the long decline along the road can be hard to perceive I guess.