Its definitely real and valid which is why the study is just silly to me and a waist of time and energy. Its like studying what is love. Love is love who cares how or why. It just is. If I'm gay who cares why I just am. To research it to me is a means to try to devalue it.
Humans are different in so many different ways. I'm not sure if knowing how or why those differences occur devalue them. If we were talking about differences in cognitive performance, we certainly wouldn't feel like understanding that would devalue cognitive performance.
The difference, IMO, is that we are talking about sexual behavior. Our culture has significant biases toward certain kinds of behaviors and these biases have little rational basis. Does it really matter if homosexual behavior is genetic or environmental? Love is love and the question of what is love doesn't make love less than it is.