If you break someones kneecaps, you may get the information they have, but you will never get anything more. After that they and their whole network will take precautions, even going as far as never communicating electronically if required. Such bullying may also easily backfire, which limits its use.

A broken communication channel in contrast is the gift that keep giving. You can get up to date information that the opponent think is confidential as it happens, and they will not take precautions, and you can continue to use the information against them, giving you the upper hand. This is why NSA was so determined to keep their actions hidden.