This isn't about "black" vs. "gay." It's about the media searching for and fabricating a story where there isn't one and completely erasing a community that is living and loving at the intersection of our movements for racial justice and LGBT equality.
Some African Americans felt "dissed" by the president's speech. The linkage of their civil rights struggle with that of LGBTQ Americans did nothing to quell their dislike of the comparison. For them, the fact that it was spoken by this president made it sting more.