As much as I like a lot of diversity in my life and I generally feel most comfortable when I am surrounded by people with different ideas, values, and opinions, there are times when I really just need advice and conversation with someone who has been there. All the compassion and sympathy in the world just cannot make up for someone who has actually walked in my shoes.
I do not rule out that those who have not lived through the same thing or things that I have can be helpful, but I think that we all occasionally feel like we just need support from a fellow traveler and I have also found that advice from someone who has actually walked in my shoes is sometimes just what I need. As a single parent, I have plenty of friends from all sorts of different lifestyles and circumstances, but I do have a few who either are single parents or who have been single parents, who can be especially helpful at times.
It is not just the advice either, perhaps you have noticed how those people who have actually been through something similar are less judgmental and more open and supportive. This might sound like a generalization, but I find that my few good friends who are also single parents (or who have been) are the least likely to pass judgment or ask obnoxious questions that can only make things worse. They seem to know how to be encouraging and supportive and say just what they would like someone to say to them.
Sometimes, we need to let our guard down. Yes, diversity is good and I know full well how hard it is to find people who have been through what we have, but having one or two people in our camp who have walked a mile in our shoes can make all the difference in the world!