Sure. That's good because they shouldn't assume that. The author isn't assuming that either; as I said, he wrote what he knew and was clear on that. I'm sure he'd be thrilled if other people wrote books covering the things he didn't know enough to cover.

That said, some GLBT people have said they find the book valuable. Even as a straight man, I found it very useful, and not just domestically. Abuser psychology doesn't just come out in romantic relationships; for example, it was great in helping me see what was going on with an abusive boss. I walked out of a terrible meeting saying, "What the hell just happened?" Later I had an inkling, so I opened up to the chapter on abuser types. In one meeting, the boss hit 80% of the characteristics of the "Mr Right" type.