Because in my experience, the "maintaining/debugging" step is almost non-existent (isn't that the point of the ORM?), and the "optimizing" step hasn't been an issue for the traffic our sites get.
> the "maintaining/debugging" step is almost non-existent (isn't that the point of the ORM?)
Nobody can agree on the point of ORMs, which is a large part of the reason why there's so much debate over whether to use them and how. I must say, if their point is to eliminate maintenance and debugging, then they are failing miserably at it.