I'm sorry to hear that Boeing take such a blinkered view of other people's improvements to their aircraft. I would have thought that any improvement that kept the aircraft flying longer and burning spares would be welcomed. I suppose that they may argue they don't want to lose new sales but it's just as likely that it would be Airbus losing new sales. Certainly, with no new 747 variant likely for years (if ever) improving the existing models would be more likely to damage A380 sales than anything else.