This is what I just don't understand. Why isn't it commonplace to use MACsec on all long haul fiber? Compared to the cost of the cable itself the added cost of

This is what I just don't understand. Why isn't it commonplace to use MACsec on all long haul fiber? Compared to the cost of the cable itself the added cost of encrypting that traffic is barely enough to register as a rounding error. The fact that tapping into fiber is possible is a shame as there's plenty of commercially available hardware that would make that a practical impossibility.