I know I'm going to be reiterating a lot of points made by the awesome people posting above me, but here's my input on this:
Does everyone have the right to tell any story they want? I think so. There's no reason why I, for instance, couldn't sit down and write a story about the suffering of Aboriginal Australians. What people often conveniently forget when talking about rights, though, is that it's not a one sided coin. Every right you have comes with a responsibility that must be fullfilled in order for your right to be exercised and respected. In my example, I would be under a tacit obligation to do every last bit of research necessary in order to paint as detailed and accurate picture as possible. It's my duty to do so, and if I don't feel up to it or formally equipped to take it on, then I shouldn't.
Will that story be as good as, or better than, a story told by a person that lives it? No, I don't think it ever can be. It can come close, mind you, because there are incredibly empathetic people out there with the ability to really get into the minds of their subjects and express their emotions vividly. But, at the end of the day, they're just abstracting a story instead of telling it. Living through something arms you with a whole other level of experience and understanding that just adds a level of detail that cannot be matched. punkarsenic's comment that mentions higher resolution is a very illustrative way to explain this.
Should people be encouraged to tell their own stories? Absolutely. But, at the same time, people from outside whatever circle we're talking about shouldn't be discouraged to tell similar stories. Here's the thing: people who are hateful, who write for the exact reasons previous posters frown upon (racism, objectifying, stereotyping) are the kind of people that have no input in a discussion like this, because it implies a level of consideration and respect that is above their current capacity. It literally flies over their heads and they're going to write their horrible, horrible story anyway. But incredibly gifted, nuanced writers can act as allies, as has been said prior, and allies from outside the group can be incredibly important. When different authors from different backgrounds write about a topic, it really hammers home to observers that the issue in question is very important and that it should be discussed and thought about. Their stories cannot ever live up to the ones told by people who actually went through everything themselves, but they have their place and their value.
And, just to add a bit of footnote to this: would I ever write a story about the plight of Aboriginal Australians? No. I don't think it's my place to tell one and I don't think I'd do a good job at it. It would require incredible amounts of research that I've neither the time nor the ability to do, and this renders me unable to tell it by default. Also, I'd rather just tell my own stories, ones that speak about who I am as a person. But, that doesn't mean that there aren't people out there who aren't Aboriginal Australians who could tell an amazing, riveting story about it that can serve as a companion to the experiences of the people inside that group.
