Forgive me for being blunt,,,, but how many oil related failures do you see in your area? 

Most things I've seen with the newer engines seems to revolve around, injection systems and contaminants in the fuel, the electronics, (wiring, sensors etc) or the pollution control system (def, egr, egr cooler, sticking vanes in turbos and of course the electronics to control it).  I really don't see many engines ventilating the block with a rod or other oil related failures.

I do realize that oil samples could catch coolant in the oil from a faulty egr cooler, but whether it would catch it before engine failure is questionable.  At least the ones I've been around failed rather quickly.

If I'm missing something that regular oil samples will pick up in the above areas please tell me how.