I have come to believe there is a mindset in the publishing industry that rudeness is essential. Over this past year, I have submitted five book manuscripts in accordance with publishers guidelines, 10 book proposals and 35 query letters, all following the instructions on the respective web sites. Of those, I received two terse replies. None of the other publishers bothered to respond at all. I do not think this experience is unusual. Whatever the actual reason, the excuse of not enough time is a stretch. A short email reply takes only seconds. Oddly, before email when they mailed back form letters is the enclosed SASE, I got a much better response rate than I do now.
Now, I happen to be editing an anthology. No matter what I think of the submissions, at the end of the reading period everyone will get a response. So, I guess there must be something wrong with me.