"Eh, ok so there is no "gay gene" as such. But if they're trying to pretend that that's the end of the project, WTF are they talking about?"
It IS the end of the project. The problem with the assertion is that the project was never DESIGNED to explain the functions of the genes -- simply to sequence them (as taxed2death pointed out). They never LOOKED for the gay gene in the Human Genome Project. Thus, the argument is something of a straw man.
I do think they will have a very hard time finding any single gene that determines sexual orientation. It's pretty clear from existing research that there is a genetic influence (likely multi-gene, and very possibly nonspecific) and there is an environmental influence, which we don't understand at all yet. Anyone who has determined "THE" reason for sexual orientation is talking complete nonsense from a scientific perspective.
There is a very good explanation for why we don't know what environmental influences cause sexual orientation. To understand a causal question like this one would have to conduct a controlled experiment. Such an experiment would be highly unethical. I suspect that we will NEVER know what environmental factors are causal. We can rule things out as causes (and have ruled many things out), but we cannot make a causal statement with only correlational data.