I define colonialism as the invasion of another territory in order to gain resources which are based there. I think that tourism may have initially been used to encourage colonialism (e.g 19th century attempts at getting Britons to settle in Australia), but with imperialism no longer welcome, I don't think tourism is conducted with such an ulterior motive anymore.

I understand worries about tourism reinforcing the stereotyped images of a culture (most worries about "Cultural Appropriation" stem from these), but it's wrong to say that tourism is a means of subjugating a culture, just as I disagree with claims that "Moana" (for all the flaws it will have) is a means of subjugating a culture...