I do not mind a "Bad" book, There is something to learn from every book, even the really dodgy ones (lol, even if the thing learned is "that is not the way to write") plus we all have our own tastes, what may be appealing to me, would not be to many others, the same applies to you I am sure. What always facinates me is the "Cusp" where writing (quality and content) and the enjoyability of the tale become intermeshed. Few books achieve that in my humble opinion. Often, to write well, the author loses the tale. Leaving you with only phrases and words, beautiful as they may be, but the story itself has vanished. To others the "Tale" is all and the quality of writing, of content, deteriorates in favour of the pace and direction of the story. Few books (again, in my humble opinion) are able to live on the "Cusp" where great writing and an excellent tale combine as one.
I am not suggesting that such books are unicorn's, as they do exist but rather that they are an endangered species as few are seen anymore.
This is not really a worry for me, I enjoy losing myself in a book, good, bad or indifferent (though I prefer it when they are good. Obviously)
and will hopefully continue to do so.