This flag explicitly includes only two groups and therefore explicitly excludes everyone who doesn't get their own color. The original flag implicitly includes everyone by explicitly including no one. What about Asians (Which itself is a group of a wide range of unique cultures) ? What about Latinos? First Nations? Shouldn't they get representation here too? Thats the problem this flag introduces, and its a problem the original avoids by design. By adding black and brown, they are taking away from that underlying theme. Its supposed to be a sign of welcome for everyone.

The second, more important reason is that the pride flag does not explicitly include ethnicites and thats the point. It doesn't fit and it doesn't really look nice. The first reason is a bit shallow: its ugly. I do believe this needs to be tackled, and that it often gets swept under the rug. That is, not particularly well there is a clear higharchy: whites at the top, blacks at the bottom and everyone else in between.

There is much to be said about how people of color are treated in the LGBT community. I'll preface this by saying I'm a brown, gay man. No, it doesn't make sense at all actually.