I'm very happy they do what they do. Cool online services often take a long time to become availiable Europe. Because of people like the Samwer brothers, that delay has a cost.
You're assuming too much. It's not adequate shelter. You'd get sick living in a shack in an indian slum or in a hut in the amazon without modern medicine plus expensive and time consuming precautions--precautions a slum dweller can't take. Read up on public health in slums, particularly slums in the tropics.
"many missionaries throughout history easily decided to go native"
Err, no. Missionaries (as well as soldiers and merchants) used to have crazy high mortality in the tropics.