I can give you several reasons why not. First of all he made a big mess, has to pick up all the crap off the floor. Second of all, he will have to remake that pizza. Third, it doesn't look like he has a lot of help and it takes about another 15 minutes for a new pie while people sit hungry. Fourth, He will likely not charge the customers and is losing money on 3 whole pies or more. Fifth, he could have hurt himself and or his customers. Sixth, he could have broken that table which could be additional losses. Seventh, he could be breaking some FDA regulation that could provoke fines. Eighth, those customers will probably go somewhere where they don't fuck around with their food when they're hungry. And last but not least, if a customer gets hurt over something stupid like this, like having the table flip on them, then that could be a lawsuit that would jeopardize his business.