What can be worse than premature optimization? Premature generalization :-)
What is so special about efficiency? Efficiency is just one of the concerns the software development orgs are facing, together with cost, utility, usability, deployability, maintainability and so on. The tradeoff between these (and the ability to choose this tradeoff correctly early in the cycle) often defines the success of a project or an organization. Focusing on one while disregarding others can be lethal.
What is so special about efficiency? Efficiency is just one of the concerns the software development orgs are facing, together with cost, utility, usability, deployability, maintainability and so on. The tradeoff between these (and the ability to choose this tradeoff correctly early in the cycle) often defines the success of a project or an organization. Focusing on one while disregarding others can be lethal.
YMMV. Watch your controls.