Excellent point!
That was just to give the caring liberals something to hide behind.
If Bieber's study were replicated today, it might come up with somewhat different numbers, but at least it would be a talking point, and a place to begin to repair the damage done by the imposition of essentialism as The Truth on the American Psychiatric Association by politically-motivated gay psychiatrists, beginning in 1973.
A substantial minority, even a plurality possibly, of APA members (there are three APA's in the world of psychiatry: I'm referring to the American Psychiatric Association [the others are the American Psychological Ass'n. and the American Pschotherapy(?)Ass'n.]) still believe as Bieber did, that there is a very large psychological/psychiatric component to homosexuality, and possibly the etiological cause of homosexuality. That is to say, that they think that homosexuality is psychological and maladaptive in origin, and my inference is that they would support returning homosexuality to the Diagnostic and Statistical Manual to its former status as a paraphilia.
But you won't hear about that from the APA. In fact, the results of the APA membership poll have been taken down from the site (which wasn't APA, but another group's) where it had been posted, or moved -- tried to check it a few days ago and the link no longer worked.