I only ask because everything you are saying, even the way you are wording it, reminds me of a lady I used to know (she was nice lol)
I genuinely don't see that is it right to stop/bully people into stopping an activity that does no harm on the basis that other people are upset that they can't/didn't do it themselves
You are right on this point, really right. But other people do have the right to question the effects of very long term breastfeeding in general, not in a nasty way, but in a situation of healthy debate and discussion, like they are here. It is not necessarily the case that they are angry because they cannot or did not breastfeed, nor is it always the case that they think women should stop at a specific age.
Please don't feel that you or longer term breast feeding mothers are being attacked. Society SHOULD be more accepting of breastfeeding in general and of longer term BF mothers as part of that group, but they aren't and therein lies the problem.
Part of the reason why I would probably not breastfeed a new child past say 2.5 years is that I wouldn't want my older dd to have to deal with the stigma attached. I have my own niggles opinions about separation anxiety etc, but they are simply my opinions and I don't have any studies to hand to back them up, only my own observations.
It would not be appropriate to advise any mother that she is wrong to carry on BF if both she and her dc are happy with it. It is a very personal and case specific choice as are most things where our children are concerned.