My kids were taught table manners, not for my sake but for their’s. I don’t want them to be an embarrassment at times when people could judge them accordingly. There may only be a handful of times in their lives when table manners are critical and it’s far better to know it than to not know it.
JL Li mentioned business dinners, I can’t imagine being at a business dinner and being thought poorly of just because I had no table manners.
I can't tell if you are joking. You are kidding yourself if you think prospective clients or employers don't notice and harshly judge table manners. I know someone who takes candidates out to lunch or dinner for one reason, which is to evaluate their table manners. For example, if they put salt on their food before tasting it, instant disqualification.
It has to do with judging a person's social skills and awareness of how to appropriately present oneself, how to create an impression, how you might represent the company if you are hired, etc. At any business dinner, you will absolutely be considered a moron if you feed your self like a child.