> Strictly speaking, this isn't a failure of the ORM itself -- it's the fault of the developer

You've got that backwards. If a tool obscures complexity such that a developer using it could be tricked into thinking their efficient-appearing code is actually inefficient, the problem is the tool. A well-designed tool makes inefficiencies explicit. "You're holding it wrong" is not engineering advice.

> ORMs are good enough for those kinds of projects.

It's all good as long as you have properly abstracted it away from your core application. The trouble with some ORM toolkits is that they encourage you to move database logic into the rest of the application and that's when the messes begin. The old school PHP programmers will know well that SQL in raw doesn't automatically mean proper separation of concerns either, but it is more likely to push you in that direction.