I have had 5 instructors so far doing my PPL, IMC and various rental checkouts. Apart from the first one that showed me a basic walk round during my PPL there has only been 1 other who actually took the time to check over the aircraft properly with me. I learnt more from him in that 10 minutes than the others put together. He quizzed me on what this does and how to check that this bit works properly, and if it looks like this then it won't work etc.
All of the others clearly had urgent business to attend to whilst I was out in the p*ssing rain or getting the Cessna tattoo on my forehead!