Dean Wesley Smith, one of the contributors to the freebie manual Write Good or Die, has a post on "But why would you... insult writers like this?"
The post is well worth reading, covering the growing habit of professionals in the publishing industry to not bother responding to queries. Dean rather eloquently points out that they do it because they can.
Previously, writers had no choice, but now the balance of power is shifting away from the middle management and to both ends of the real business--connecting writers and readers. Over the course of my own career, I watched the lack of response happen. In the late 1990s, you could pretty much count on getting a form rejection within three months of your submission. That was when publishers still looked at manuscripts.
After that, publishers started requiring agents, and agents responded to their newfound power by raising their commission from 10 percent to 15 percent. The corporate publishers merged, smaller presses folded, and soon we had the Big Six that we know today, although there are still some established small and specialty presses. All this moved the selection of marketable books into the hands of a very few people, which also caused them to be busier than ever.
The net result was that there were few of them and many, many, many writers. It was actually easier to ignore almost all writers, because they really only needed a few. Even if the 100 best books ever written all showed up at the same time, they'd still only buy five of them. Same with the worst 100 books--they'd still need five.
But that's not an excuse to ignore writers. If a writer spends a year working on a manuscript, even if the story is dog slobber, it deserves a "No, thank you." Of all the ways traditional publishing contributes to its own demise, I can't help but feel the "Only responds if interested" policy is a subtle but revealing detail about where modern publishing has arrived.
Perhaps the decline was inevitable, but it could have been embraced with a little grace, and then perhaps more writers would be saddened at the loss. As it is, we're not even sure it's any loss at all.