I think it's because when we invent television we don't lose anything. Once we show these people the modern world, there is no going back. It makes it a difficult moral dilema.

When we invented cars we lost our own culture’s tradition of riding horses. It used to be the case that everyone knew how to ride a horse, now only a select few decide to preserve that tradition. Even they ride only for sport and fun, a cheap imitation of what it meant to ride a horse 200 years ago.

Cars viciously destroyed the role horses play in our society, that part of our culture is forever lost.

(I’m not sad.)

But people can still ride a horse. A contacted tribe can never become uncontacted again. BTW I have no idea whether the right answer is to contact them or not, I am just explaining why it is a moral dilemma.

Good point, but we do have examples of people who choose to ride horses as part of their daily life: Certain Amish and Mennonites.

They know all about technology, they just make certain choices about it and we have found a way to get along with them making those choices.

The individuals in the tribe should ideally be allowed to do the same. (I know that’s not easy. Said tribe would be forever changed if we explained to them what they could do in such a way that they can make an informed decision.)

The whole question of whether we should in principle allow access seems easy to me but I also think that many massively underestimate the enormity of that task. I fit the culture I’m living in because my parents invested massive amounts of energy, time and money over two decades to make me part of that culture. I would guess that a similar effort would be required for the individuals in that tribe and they have no parents to help them along.

Much can go wrong. Individuals of the tribe might end up much more miserable or, indeed, dead. This is one of those problems that seems to me to be in principle easy but in practice extremely hard to actually solve.