A recent study by the World Economic Forum measured the openness of countries to foreign tourists and the tourism industry in general. Ranked from 1 to 140 (140 being the least welcoming), you might be surprised to learn that the United States appeared at a paltry #102 on the list.
Mongolia's reputation is still feeling the effects of its past communist government. The country's low rating stems mostly from the fact that its private tourism industry is a mere 20 years old. As the least densely populated nation on earth (only 3 people per square mile), it's no surprise the local population would be wary of a large influx of tourists.