Why don't e-publishers want Young Adult books?

I've just finished writing the first of a three book of the young adult fantasy and am now in a quandary about what to do with it. In order to send it to a mainstream publisher I need to acquire an agent and they are as difficult to find as a publisher.
This leaves me with two alternatives: one - self publish or two - offer it to a digital first publisher.
I decided to investigate both routes in my usual haphazard, nonscientific way. My research is as follows.
There are very few  digital first publishers still running a young adult line. The ones that do I checked the Amazon rankings of their books and they were all far higher than for my Regency romances. This puzzled me - I thought teenagers were buying more books and that YA was a growing market.
I browsed various forums and message boards and to my astonishment most seem to be saying that teenagers, in fact, have not embraced the digital reader. They prefer to read print books and Smart phones/iPad etc are used for communication and game play - not reading. It is adults that are reading on the Kindle not teenagers.
I also read in many places that those that are buying for digital readers in this genre are mostly adults who like reading crossover fiction.
I know that Hunger Games, Twilight, Harry Potter and Amanda Hockings's books have sold in their millions but they seem to be the exceptions.
The general consensus of opinion is that YA digital fiction is not selling well enough for the publishers to continue stocking them.
If this is true then I might as well self publish  or put the book to one side until things improve.
What do you think? Do teenagers prefer print books to digital? Are the main buyers for YA e-books adults?
Looking forward to hearing your opinion.
Fenella

Should negative reviews be published?

I have just finished reading an excellent historical novel that I shall be reviewing for the Historical Novel Society later this month. I've also just read one that I think shouldn't have been published.  This made think about the reviews I've received for my books as well as the reviews I've written for other people.
I always review a novel honestly. I try and avoid doing any for friends and people I know just in case I can't give them a five-star, glowing report. If a book is excellent then I say so, if it's good then I say that, but also mention what, in my opinion, could have made it even better. With a poorly written book it's much more difficult.
I had a bad review and a five-star review for the same title on the same day. Reviewing is subjective and the comments should make that clear. What can be enjoyable to one person is another's worst read. One person may like the subject/style of writing another might not. That said - a badly written/edited book is just that.
As a writer I know how hard it is to finish a manuscript. If a publisher has put this book out, then they must have believed it was as good as it could be. I don't enjoy being negative about someone's efforts, but there would be no point in having reviews if the only ones that were ever written were positive.
However, I make sure  my comments are never directed at the author but the book. I've never forgotten the critique I received when I was an unpublished writer which told me I was ridiculous. I can also honestly say that I've only received a very few downright bad reviews. I could quote what was said in all of them - and by whom. I've had many glowing accolades and 5* reviews and although they were all a delight to get, I don't remember what was actually written.
Which brings me back to whether anyone should ever write and publish a bad review knowing the potential damage it can do to an author's well-being. I'm not talking about self-published books -these are another thing entirely.
What do you think?
Would it be better if the bad reviews were not published? The writer would know the reviewer didn't  like their book by the absence of a review.
Until next time
best wishes
Fenella