Simple. TLS ensures data integrity and protects it from eavesdropping. Here is a conversation between Alice and Bob:

Alice <-TLS-> Bob

In this scheme, only Alice and Bob can know the details of a conversation.

Another conversation with Kevin reveals another scheme:

Kevin <-TLS-> Bob

See the pattern? Both Alice and Kevin shared their information with Bob.

Now imagine that Bob is a Big Co. And it has hundreds of millions conversations every day.

In this way, Bob is able to gather big data about all the persons he ever talked to. And because TLS only protects data in transit, Bob now has the privilege of an exclusive access to the gathered data en masse. No other person in the world would be able to access it as Bob claims a total ownership on it.

What Bob would do with data? It's an open question.

One scenario is to build a graph of relations between the persons and then target them with ads. Another scenario is to target all the persons who ever dared to show signs of non-conformity and disagreement and put them to jail. The possibilities are endless and nobody would be able to prove anything because TLS helped Bob to deter all the eavesdroppers. And now he has the ultimate power to rule the world.