"Gets out to who?" demanded Ringstorff. -- Crown of Slaves by David Weber and Eric Flint.
One of the first things we "learn" in elementary-school English or Language or whatever the class is called in your school, is that there are subject forms of pronouns and object forms of pronouns. I put that "learn" in quotes to emphasize that, perhaps, not all of us really learned that distinction. Perhaps, recalled it long enough to get the question on the quiz correct, but some/many of us never really learned that fact, never really took it into our being. That must be true, why else would folks have so many problems when confronted with the needs of a compound subject involving a pronoun? Certainly, we've all heard people start sentences with something like "Jimmy and me went...." When encountering such, those with any modicum of learning and care for the language wince (visibly or not), because all such people know when to use "I" and when to use "me."
Why, then, do people have such problem with "who" and "whom?" They are both pronouns, with the former being the subject form, the latter, the object form. As for reflexive pronouns (and there will certainly be a blog on the misuse of those in the near future!), I feel that some speakers/writers feel that using "whom" is simply a high-class thing, meant to indicate that the speaker/writer is not just some peon off the street, but is, in fact, high-class or posh. Of course, the only thing that using "whom" as a subject indicates is that the speaker/writer simply does not know how to speak/write correctly.
David Weber's extensive so-called Honorverse is one of my very favorite sci-fi series and I have read and re-read it. I also find it of interest that Mr. Weber does all of his writing via voice-recognition software (VRS). While some might consider that rationale enough to cut him and his publisher, Baen Books, some slack as far as lapsus go, that makes no sense to me. Catching mistakes, whether due to mis-typing on a keyboard or due to errors in interpretation by VRS is still one of the many items in the purview of both author and publisher, particularly the latter.
Because the series is set some 2000 years (give or take) in Earth's future, other apologists might argue that the language has changed and eliminated "whom," using "who" for both subject and object (as in the transformation of "you" from being solely a second-person plural pronoun). I can guarantee that the language will change in that amount of time. However, that change will be so extensive that were Mr. Weber to actually write in the English of 2000 years hence, he would have sold damned few books, as no one else would have been able to understand the language! Thus, with the speciousness of that argument exposed, I do not understand why so many authors and publishers continue to utilize incorrect grammar, using "who" where "whom" was the correct pronoun. They certainly wouldn't use "Jimmy and me went...."