Whatever the definition of community of interest is, it has to be applied equally. The way the boundaries commissions have traditionally applied it has often been to look at smaller communities with less population. Why don't visible minorities or suburban voters also constitute communities of interest? Their interest should be taken into account. When they're underrepresented, are their interests being taken into account? I don't believe so.
Whatever the definition is, it has to apply equally across not just geographic groups, but other kinds of groups as well.