I am affraid it has got nothing to do with stupidity , or ignorance, and saying so is not fare to the engineers.
I believe it is simply a shortage of staff. Responsibilities of a few people piled up on just one person who ,if doesn't perform, gets b....cking!
And I don't think this is about to change. Our turn oround takes 25 to 30 min and believe me we are under pressure. We can relax in cruise ( mind you not for long in my company) but I dont think engineers have the same comodity , and work round the clock.Just my thought