You can call it a heuristic or a guideline, but I consider them essential. Perfectly rational agents without empathy can commits massive acts of evil trying to achieve their goal. Or as the proverb says "Road to hell is paved with good intentions".

And I don't think short-sightedness or ill-informing was ever an integral part with arguing about how empathy is essential to human live. IIRC there was an example of perfectly informed and rational computer of super human intelligence who was told to calculate a particularly difficult equation, to which he promptly restructured all matter on earth, including people into a giant super-computer.