I'm hostile to bad ideas, not to the people who have them, though when people get wedded to bad ideas it can lead to some personal animosity.
You may think that this is a logical extrapolation. Few would share that point of view.
Absolutely never. But I have have seen your reactions to my designs which have included ferrite beads/chips.
But not everybody reacts as if they do.
They knew they needed to learn more. If you praise them enough for what they have learned, they can survive being told that they haven't learned all the obscure facts that they needed to.
Part of the job of a supervising engineer is getting the junior engineers to talk about what they are doing, and that tends to include what their lecturers had told them. The education can move both ways, though some lecturers weren't up to much.
It's easy after the event. At the time it's a judgement call.
I didn't enjoy being rude, but it turned out to be only way to get the message across.
It wasn't a brain scanner, but a scheme to combine measurements taken lots of ultrasound beams crossing the body in different directions, in much the same way the brain-scanner combines results obtained by measuring the absorbtion of lots of X-ray beams crossing the brain in different directions. Ultrasound beams get deflected by structures in the human body in a way that X-rays don't - think lenses and mirrors - and that wasn't taken into account. There was a scheme in another lab that sort of worked - it didn't turn out to be useful - which mapped the local speed of sound in breast tissue so you could work out how the ultrasound beams were being bent