According to the passage, why many tourists are now less interested in

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the Questions from 38 to 44.
Back in the 1980s and early 1990s, when Africans first realized that tourism might be a way out of their desperate poverty, they built big concrete hotels on the beaches of Kenya, South Africa and other countries. For some time numerous charter flights came from Germany and Italy. Tourists were hoping to see lions in nature reserves - but also expecting to eat sauerkraut and enjoy the other comforts of home - packed into overcrowded resorts that were trying to look like the Mediterranean.
That was then. Fortunately, a new kind of travel is in fashion now. Today's tourists are leaving the European-style hotels for more authentic experiences, like horseback riding through the bush. Sitting by the fire at night after a typical dinner of meat stew, pumping leaves and wild grass, they listen to the local Xhosa music, provided by a small, locally run firm called Amadiba Adventures. The money earned will provide the Xhosa tour guides with incomes two and a half times the average local wage.
In many ways, this vacation represents the future of global tourism - an industry on the road to fast growth and change. Despite difficulties, international and domestic tourism is expected to boom over the next two decades due to a rise in global wealth, improving transport technology, cheap flights and the use of the Internet as a travel than ever before. The World Tourism Organization expects that number increase to more than 1 billion by 2010. Tomorrow's tourists will come from new places; the number of Asian, and particularly Chinese, tourists is predicted to explode as that region becomes more integrated into the global economy.
Future tourists will also want to do different things. While sun-and-sea tourism still dominates, overcrowding and time pressures mean that the standard two-week beach vacation is less popular. Rather than spending two weeks on a beach, workaholic Americans and Europeans are taking shorter but more varied trips, causing the rapid development of adventure travel, ecotourism, cultural tours, spa holidays, cruises and sports vacations in ever more distant places: China, the Maldives, Botswana. Western travelers who have "been there and done that" choose more exotic, individualized experiences. Local governments and firms are trying hard to satisfy this new demand, which offers them the opportunity to make huge profits in the market.
(Adapted from Oxford Exam Excellence by Danuts Gryes et al.)