This had been known for a while. Yet there are different considerations besides fastest boarding time. First, people traveling together tend to sit next to each other, so ordering by "columns" instead of rows breaks them apart in the queue which may be either uncomfortable or downright infuriating if you travel with young kids.

I can imagine that letting passengers take their seats at random results in pretty fragmented available seating so if you travel as a large group and want to seat together, this might be a problem too.