Major publishers are in trouble. Publishers Weekly reports declines across the board at all five major publishers. What is happening here is not new, as much as publishers would like you (and themselves) to believe. For the past four to five years, publishers have found growth almost exclusively through acquisitions, mergers, layoffs, and the largesse of their primary retail account, Amazon. All of those forces have run out of room. As self-published books took off and began commanding a growing share of the book trade every quarter, publishers were able to weather…