Never take unecessary crap from an instructor BUT the onus is also on you to be fully prepared for your lesson. There were times wher I was yelled at by my instructor probably due to him at witts end because all the hard work he put in was not being replicated at my end and the end of my other class mates. I think it is a two edged sword (cant believe Im defending circuit heros
), put in the time out of the aircraft getting it right and frustration levels in the aircraft will be far less.