Ashkenazim should not be envious of rice on Pesach – and not just because of a month of Selichot.
Apparently, kitniyot is connected to new medieval agricultural practices developed in Northern Europe that involved growing beans same fields as grain in different years. That would raise a concern. This practivce was responsible for Northern Europe drastically increasing amount of available protein from beans, while Southern Europe relied on animal protein. Animal protein is limited by amount of grain you can grow. Total amount of protein determines the size of the population.
And that is how an obscure group that come from a 100 Jewish men now constitutes a majority of Jews, while lumping an incredible diversity of genes and minhagim as “Sephardim”. This is hinted in Hagada as it says Jews left “b’ yad RAMA” and, of course, by the enormous amount of protein in Karban Hagigah and Pesach that we consume!