'Which one is on duty today, the nice one or the grumpy one?'
Already during our theoretical training, we were told that bad behaviour on the radio can be a serious safety issue, and we should always take this with cool attitude, and just ignore for the sake of safety, if needed.
Case in point: back in year 2000, a C-172 crashed and burnt on takeoff from our airfield, killing 3 and seriously injuring 1 person. The AFIS was provided by the glider operations in progress that day, and the person on duty was a grumpy one. He shouted twice at the low time pilot preparing for his takeoff, first when the pilot wanted to take off opposite to the glider winching direction due to recent change in wind direction. Second time the AFIS shouted at the pilot when he was in the middle of his take-off checklist, testing the flaps. The grumpy voice was asking why was he such a turtle, and urging him to hurry up now and start the take-off roll immediately, due to incoming gliders that want to land soon.
The effect was predictable, the poor guy took off in a rush, with flaps forgotten in landing position, against a slightly rising terrain. He didn't have the experience to realize this and solve it somehow, even with a controlled crash landing ahead. Instead the landing flaps were retracted in one go and the aircraft entered a low-level turn, stalling and falling from about 30 meters.
This was a sober reminder to us, that safety is first, angry shouting to be ignored at all times, and if necessary, handled after landing with a phone call or a personal visit.