As has been said by one or 2 sensible people... no they are not "wasting" money, and nor will their money run out when the oil runs out for this very reason. The leader of Dubai is actually a very intelligent man, and realised that all Dubai's resources came from oil, and that this would indeed not last forever, and so decided to invest it wisely into many business ventures via the Dubai Investment Group. Not just building a HUGE tourist industry in the country itself, which we are all well aware of with the future theme park projects scheduled for that area in the near future, but also investing in companies, Football teams, literally LOADS of stuff to ensure the countries money doesn't run out.
Also on the point of this specific firework event being a waste of money, any one who works in management/business etc will know all the mind-numbing planning and financing which goes on behind any venture, and this will be no different. They will have come up with project budgets and potential revenue by putting on the display, and compared it to other means of advertising/opening etc, and decided that this was a profitable and worthwhile investment. Very very few things happen because the owner of something decides "I want that one", and is one of the top reasons theme parks so often disappoint us picky enthusiasts by building less than mind blowing rides.
