Hi
JS
'you can teach a monkey to ride a bike, but you cant teach it to fix a puncture!'
I have heard this spouted in many forms over the years usually by people who have limited experience of line engineering & dealing with crew. It is not a fair comparison as although both engineer and pilot have a vast technical knowledge of their aircraft, their respective training, knowledge & experience are focused in very different ways.
Example,
XXXX system has failed
An Engineer will think - How can I isolate or eliminate the fault - How am I going to fix it ?
A Pilot will think - What functions have I lost, How does it interact with other systems - How am I going to manage without it ?
As Eric said pilots are no different to anyone else - they command the respect they deserve & they acquire this by the manner in which they deal with situations and people - most are sound, some are exceptional and very occasionally you meet one who clearly has no aptitude for the job, in the air or on the ground. The same applies to engineering really.