Totally agree that toddlerhood, early childhood and beyond for that matter sees a normal, gradual increase in independence and an increasing repertoire of comfort strategies. Breastfeeding allows for this beautifully, as a child cannot be forced to breastfeed. Typical weaning in cultures which have no social problems with bf beyond (say) a year or so happens over quite a long time, with the gaps between breastfeeds stretching to days and even weeks, with maybe short periods of more frequent bf as the child expresses a wish for this to happen, and if it's convenient for the mother.
This is not interfering with the normal, natural process of a child's emotional and psychological development, but rather it supports it. Obviously, it's not essential for normal, natural development, but there is nothing in what we know about normal, natural development to suggest there is anything wrong with it....and mothers should be fully supported to continue to bf as long as they and their children wish. We already know that there are measurable health benefits.
Of course, if a mother thinks it's distasteful, or 'wrong' , then she probably wouldn't be doing it anyway!
Why anyone feels able to judge another mother, or her child's propensity to independence, on the choice to bf beyond a year (or not) is something I fail to understand. Live and let live