A quick google of this (which ended at wikipedia, obviously

) reveals that EMAS is apparently designed for runways
without space for a Runway Safety Area, which is probably why. I daresay in most other cases an RSA is probably better because the aircraft's undercarriage isn't wrecked, and my common sense tells me it's more common for newer pilots to persist in a poor approach instead of going around, bringing them into the RSA, than airliners careening down after losing throttle response.
An EFATO - Engine Failure After Take-Off is probably the worst thing that could happen that would require an RSA/EMAS, and if your plane's going to smack into the runway...well then, it's going to smack into the runway, soft concrete or not.
