Do you... eat like a caveman? Utensils are there for a reason -- so you can eat like a gentleman. Shoveling food into your mouth is not something you should subject your date to. Same goes for talking while chewing. Not only is it unpleasant to watch at a time when your job is to be easy on the eyes, it's a red flag that says you're a little short on self-awareness -- an important characteristic in a mate.
First, they assume that all women have superior dining skills.
Second, they don't understand what men are doing.
Men have spent years and years growing up as boys being pestered by their mothers to keep their elbows off the table, to use their forks, wipe their mouths, don't talk while chewing, etc. Do you think they want to be pestered for the rest of their lives by their wives as well?
A guy behaving just as he would normally behave, is a filter. If a woman can overlook his disgusting habits, and focus on the things that they love about him, then she passes the first test. Maybe she's has potential.
If not, there are other fish in the sea.
Remember gals, a date is not a one-sided affair where you get to decide the outcome. He's also trying to figure out if you're worth the endless trips to the hair and nail salon his paychecks are going to be supporting.