Fordama wrote: That's what they are saying in the introduction about previous studies, not this particular study.
Introductions are important, but they aren't the conclusions.
"CONCLUSIONS: Familial factors, which are at least partly genetic, influence sexual orientation."
No equivocation there at all. No fancy interpretation needed.
...no "reading the whole thing" apparently needed by you anyway.
You might also have missed, further down, one of the five weaknesses of this study to be
...Second, despite the reasonable sample sizes, the relative rarity of nonheterosexual sexual orientation in general population samples results in quite low statistical power
Did you notice the study on which you're trying to hang your whole argument has LOW STATISTICAL POWER?
And, finally, you must have missed the equivocation further down in that abstract that noted:
These results suggest that genetic factors may provide an important influence on sexual orientation.
Did you notice MAY