Thats the usual stated justification. Do you think most people travel actually for the bolded reasons mentioned? One expands their minds through learning, reading books, educating themselves. Not by having an "authentic" experience in an all inclusive resort designed to limit people to exposures to surrounding areas.
In anycase those incredible diverse people exist here, come here, or live here in our cultural mosaic country. Try taking Via Rail across Canada. You'll meet as many people from around the world as Canadians taking the train. You'll get to know them too as the train affords long periods of time to connect.
Anyway
7 Reasons Why the 'Authentic' Travel Experience Is a Myth - The Atlantic
Now think of how many people travel on Cruise ships, river cruises, tour busses. The people they meet the most are right from the Western world they live in. Indeed much of the travel industry is designed to LIMIT actual experience and exposure to areas and conditions that the tours would prefer you not see.