Easy to say, harder to actually act on. Publishers’ room for manoeuvre is limited by numerous factors and they are far from unaware of the dangers posed by Amazon and other would be monopolists:
As some authors have pointed out, even if you take advantage of Amazon’s self-publishing options to avoid having to get a traditional publishing deal, you’ve really just exchanged one corporate overlord for another. For most writers, the ideal would be an industry with multiple players — but unfortunately, their own publishers have helped make that even less of a possibility. And Amazon is the major beneficiary.