Do the teachers have assigned seating for lunch as well, or are they allowed to freely associate with whomever they want? One of the arguments against home schooling is that the kids miss the opportunities to develop social skills. Forced association is worse in my mind than no association. How much confidence and comfort will the children have in their lunch neighbors that they will open up and enjoy the experience? How much of their total lunch period are they subjected to the forced association? If assigned seating is okay for lunches, what about on a school bus? I could make a better argument for assigned seating on a school bus for safety reasons than the needless oppression at lunch.
I get the feeling that the faculty at this school has assigned seating for faculty convenience. They do not care if they alienate the students. And alienated students are not the most receptive to classroom instruction. To the faculty the kids are just an inconvenience they have to put up with while they pass the time necessary to earn their salaries.
I don't know --- but in many workplaces, you go to lunch or break according to a schedule --- not just because you need to socialize with your friends. Actually I think there should be more choice --- but rather than the father promoting the idea that social time is the only important thing about school, it might be better if more parents believed schools are for education and learning. Here in the high schools, most of the kids take off in cars at lunch time and it's a problem.