But, also, with well meaning people who may not be aware of cultural differences. But, I think that goes both ways. Well, let's stop a minute here. Let's talk about who came to whom asking for what. I think if they are not invited, the burden falls more on them.
Outsiders can be very demanding.
But, you know, our purpose in this life isn't being someone else's dissertation. For other cultures it might be an intrusion. However it may or may not be viewed, I think that the burden falls on the univited stranger who approaches the tribe. The situation is different in the case of a tribe asking someone to do the work. It isn't terriblely useful a thing.