I looked at those photos as well. After doing so, I have come to the conclusion that there are segments of our society where mental illness has ravaged the spirit and mind to the point where absolutely nothing is off limits, no matter how perverted or disgusting it may be. These perverts have reverted back to crude animalistic behavior and left whatever shreds of humanity they had behind them.
Science should re-classify these perverts as a new species, completely separate from human beings.
I know gay people who think the Folsom Street Fair is revolting, too. The participants represent a very vocal but small minority even among gay San Franciscans. Just egos that feed off of the shock they create.