Having received several patents myself, I can assure you this is not the case. "Dilligent prior art search" in an area they are not experts in requires days. Last I checked (in 2011, I think), the average time spent by an examiner on a patent, from submission to grant (or refusal with no redress) is 8 hours. Regardless of how good they are at finding prior art, that's not enough time to be "diligent".
I'm basing my statements on the real life experience of my self, colleagues and patent attorney. What are you basing your statement on?
8 hours is an oversimplification that doesn't count things like the automated preliminary searches performed elsewhere. Boiling down the invention to its basic elements, determining the delta, then finding prior art is a science.
wrong - they perform diligent prior art search - and believe it or not ARE experts at that.