I never said that commercial imperatives should be allowed to override common sense. I'm just saying that it does happen and this is why it is part of the syllabus (I think. I don't really know because I am not an instructor).
"..so..to lose an a/c and crew every now and then is OK????"
I guess I'm not really defending the crew more the exercise. Perhaps they were pushing the envelope? Who knows? Maybe they were being careless or neglectful? Aviation is terrible unforgiving.
Of course I don't think it's OK to lose planes and crew but flying is a risky business. How does that saying go?