I have found the big-name publishers to be as untouchable as the book I bought to tell me how to solicit my books to publishers said they would be. Big-name publishers do answer query letters ... eventually. However, I would rather spend time waiting for an Ovaltine decoder ring to come in the mail. After following all the procedural stuff set forth, a wait is better rewarded when one gets something that is not all it was pumped up to seem to be. Hands down that beats getting a piece of paper that says, "We're sorry, but did you think you did something important?" Some of the reject letters let me know that at least some human being at a big-name publisher actually read my query. I knew that because they would indicate the name of my book in the rejection letter. That almost seemed encouraging. Still, most would simply send the same xeroxed form letter they sent to 99.9% of the query letters they found in their "no need to hurry" bin. Half of those would not even bother to make a xerox of the original rejection letter. That seemed to have been lost long ago, and for years they had been copying copies, yielding poor quality-off center reject letters. I wonder if any of those companies understand karma?
I also found the print-on-demand "publishers" I trusted to be untrustworthy, if not outright scam artists. Because of my experience with those, I bought some ISBN numbers and became a print-on-demand publisher myself. So far, I love myself as a publisher. I haven't screwed me once on royalties, and I never have to wait more than a few seconds for a rejection.