Gosh, I've tried to avoid this thread but it calls to me! haha ;-)
I live in Maryland where we eat a LOT of steamed blue crabs. If you haven't had this experience, they steam them live and serve them whole. You need to open and clean them and extract the meat.
Now, there are a couple/few favored variations on how to properly clean and eat a steamed crab but they are the same in the main.
And cleaning one properly is key to getting the most meat out of the crab, avoiding the bits you shouldn't eat, and making it an enjoyable experience.
And how to clean a crab is NOT some instinct that we were born with...its taught and passed down. We often see people on a crab deck/house who are not familiar with crabs and struggle to get anything out of them aside from Old Bay in their eyes and fingers cut on crab shell. A few pointers will often help these folks enjoy there experience rather that feel it was a lot of work for very little.
Now, that doesn't mean that I think being a self-righteous and judgemental prick about it is the right way to help people eat crabs. But it really isn't just "well, anyway you do it works fine". It does not.
We used to have a skeet tournament in my area, big shoot with 120 competitors, and it was called the Lobster because we have cooked and served up to 600 chicken lobster (1 and 1/2 lb type of lobster). My dear friend ran it and I was always on the lobster cooking team (incredible that we never blew the place up with 5' propane tanks and burners that looked like something off of the ass end of a fighter jet. LOL
AND I was taught at least one way to clean a lobster that I was completely unaware of. First, ring the tail off. Then, with a sharp sturdy knife, make a left-right slit by the anus (well, not sure what its called on a lobster). Push your thumb in this slit and push the meat out the front and Robert is your mothers brother.
So, I wasn't there and have no real idea how much of a butt head this guy was....but perhaps he really was trying to help...just with lousy bedside manners???