Is it bad to be a 'board tapper', i.e. to tap your knife rhythmically when you're cutting vegetables?
I know, this isn't really an answer, but it's a bit long for a comment:
There are people in this world that get annoyed by different things that don't bother other people.  For some of those people, it's noise ... someone tapping their foot, chewing gum, etc.  It's possible that there's a legitimate reason for this pet peeve, but sometimes it's something really odd like 'I had a friend who used to do that, and my partner left me for them, and so when I hear it reminds me of that' ... but it's subconscious, and they couldn't explain it without a year or two of therapy.  I've also known people who were sensitive to sound (and he complained that I spoke too loudly ... but he always spoke loudly, and I'd subconsciously match my levels to his ... and he hated wearing hearing protection).
For reasons that most other people would understand:

The person may be using sound cues in their cooking (how something sizzles as it hits the pan, or how the sound changes as something is frying), and if there is too much noise, they can't hear those cues.
The person may have difficulty concentrating (possibly even ADD), and they find the noise distracting
In a noisy kitchen, people have to talk louder, which means that other people have to talk even louder ... and after a while, the noise is just unbearable, and in the US, can actually become an OSHA violation.
A noisy kitchen may cause people to not hear or mishear instructions, resulting in slower or bad service.

Of course, if the chef is also shouting at people all the time, then it's difficult to accept the above items as good justification.  (except maybe #4).
There have been a number of articles on noise levels in restaurants in the past few years and most focus on the patrons (and there are even apps for patrons to track noise levels, but many of the observations about lack of sound dampening still hold true:

https://www.vox.com/2018/4/18/17168504/restaurants-noise-levels-loud-decibels
https://www.theguardian.com/food/2019/may/09/great-food-but-please-do-something-about-the-noise-the-battle-for-quieter-restaurants

Sometimes, we have to factor in multiple considerations when deciding how to do something.  In project management, there's the adage of &quot;good, cheap, fast.  pick two&quot;, in how you have to sacrifice quality, cost, or speed and can't have all three.  Some chefs will cut off the top &amp; bottom of bell peppers so that they can make equally sized sticks.  I cut off the sides and bottom so I waste less.  Neither way is &quot;bad&quot;, but we just have different priorities.
In your particular case, the chef has decided that the noise level (or at least, lack of tapping noise) is more important to them.  Someone else might optimize for speed and be okay with a certain level of noise.  Someone else might have space for you to do your prep further away so you're not bothering them.  There are just different trade-offs to try to get to the optimal solution for a particular situation.  And it may not even be constant with a given chef -- someone who would otherwise prioritize speed might have a hangover and have a day when they'd prefer quiet.