1. Attendance can be sparse
2. Even if there is a good turn-out, the audience often consists of... grown-ups!
Picture book writers can get an audience by working with the librarian to promote the appearance as a storytime that just happens to feature the writer of one or more of the books. My mom, author of "Hi, Pizza Man" knew she couldn't build a whole program around one short picture book, so she developed a whole pizza-themed storytime, complete with masks for kids to act out her book. Parents brought their kids because it sounded like a fun program.
But it is much harder for a middle-grade or teen book writer. Even if he or she has flogged social media nearly unto death and sent notices of the appearance hither and yon, this will at most generate an audience of - grown-up fans.
Now, to this librarian, an audience is an audience and I'm happy to see them, no matter how old they are.
But my writer friend protested that writers like to meet their readers, and would like to think their readers want to meet them. Which makes absolute sense.
But the more I think about it, the more impossible it seems that we'll ever get older kids and teens to come in droves. Sure, some authors have a huge and avid fan base and will certainly attract a big audience of kids or teens if they appear. But it's unlikely that they'll even hear about an author appearance if it doesn't happen to occur right at their library, since kids and teens don't follow twitter or author blogs. And let's face it, older kids and teens have a lot of autonomy when it comes to how they spend their time - and mostly, they will not choose to attend an author program if it's the slightest bit of bother, even if they have read that author's books (which is unlikely).
I can understand n. While meeting authors thrills me to the point of speechlessness, I don't seek these occasions out. Why? For most of us readers, it's about the book, not the author. In some cases, I don't even want to know what the author looks like, much less meet him or her. It's simply beside the point.
And that's fine, isn't it? Sure, librarians will still strive to get kids and teens to attend children's and teen author programs, because it's cool for kids to see that a real person created that book that transported them so magically - and that maybe writing (or illustrating) a book is something they might do themselves one day. And writers do like to meet their young readers face to face.
I'd suggest that the best way for writers to meet kids is to make presentations at schools. Make arrangements with the teachers beforehand so at least some of the kids will have read the book - and then the writer has a captive audience (and one that is probably fairly grateful to be listening to an author rather than doing fractions).
But the best way for librarians and writers to collaborate is to work together to get those books into the hands of kids. It's okay for writers to talk to a big crowd of librarians, teachers, and other grown-ups who work with youth. Why? If they get all fired up, they'll read the books and then booktalk/handsell/promote the heck out of them to the kids they come in contact with.
And kids do listen to librarians and teachers about books. They won't try all the books we recommend, but they'll try a few. And if they like those books, they'll try a few more.
And that's the connection that matters - a young reader reading a writer's book. A match made in heaven.