Yes, "How are other fields doing" is a question that can be asked - but it is one of the least interesting ones. Suppose that every other industry is at 40%. Or suppose they are all at 60%. It doesn't change the fact that ours needs to seriously deal with it. (And as seen by ~1/3rd of the comments in this thread, is more interested in splitting hairs.)
Fine, why choose tech then? Are they biased? It simply doesn't make sense.
If they want to help women, they could perhaps start in an industry where it's most likely to be a problem (and I'd bet it's somewhere where women are doing low paid job). Here's why - we probably already know at least a partial solution, just look at what are the other industries doing. You don't get either information without a survey.
Work in tech.
So yeah, they are biased in wanting to get their industry in order. There is no ulterior motive, here, and no reason to get so defensive.
I think that these "unwanted sexual advances" may come from the fact there is power differential, i.e. hierarchy and bosses. Maybe we could try to eradicate that first, that is, have more cooperatives (democratically owned and run companies)? In tech, these would be pretty easy to set up due to low investment requirements..
You claim this is a problem. Here's a simple solution: Make tech companies segregated by gender. What about that? The thing is, I presume, people who did the study don't want to solve a problem of "unwanted sex advances" in the workplace. They want to solve a problem of not enough women in tech. And this is not the way to go about it.
It is also an interesting question, and I am genuinely curious. I also doubt women actually choose the career based on amount of unwanted sexual advances, and having the numbers could finally put that stupid theory to rest (if it's false, of course, maybe it's not, I dunno; but based on the above provided link, it probably is false).