Series or franchise?

Many authors already established as authors of 'Adult fiction' have recently taken the leap to teenage (or 'Young Adult') fiction. This is probably because the market for YA fiction is currently large and thriving. Whatever the reason, I realised recently that these 'Adult' authors always seem to do so in series. Usually these series are more like a TV series than book series - the end of the book leaves you with more questions than you had at the beginning. No book in the series can stand alone, each is a chapter in the series. (There are some exceptions to this, for example Ally Carter who began writing for adults and then switched genres, has the Gallagher Girls series with the same characters but different stories. Each book is it's own story though they link.) I can name several authors - Lili St. Crow, Andrew Klavan, James Patterson, who've done this recently. I apologise if you're a Maximum Ride fan. I sort of was for the first three books, before I realised it would never end and never make sense.

I have nothing against series. If I've loved a story then often I'll want to return to that world. I just feel that each book should be whole and complete in itself. Write a book, conclude it and THEN decide to write another one. Some authors who do this well are Shannon Hale and Jaclyn Moriarty. Of course, some stories have too much plot for one book and need to be in a series. The author will have the whole series planned (I'll use Stephenie Meyer as my example here, though I've never read her books). So if it's not a series that I object to itself, it must be something else. A franchise maybe?

Maybe it's when I feel like an author hasn't written a book to satisfy the reader, they've deliberately NOT satisfied the reader to keep them coming back, to keep the mysteries. I want authors to create stories, not franchises. If those stories happen to connect, that's fine. Often the writing is good, they're enjoyable books, but they're blatantly a first-in-a-series and it's starting to drive me CRAZY. I don't want to be too judgemental as I know authors have to sell books to make their profits, but if the author doesn't love the book, how can they expect me, the reader, to? It isn't just the 'Adult' authors who do this, it's just that they seem to do it a lot. Because this is how 'Adult' series work or because they think teenage fiction is easy to write?

This isn't a slam on 'Adult' authors for trying to write teen fiction, I love it when they do. If I enjoy their book I'll check out their other books for adults. Just please make a story that has a beginning, middle, end. Over one book, over four, I don't really care (though Adult authors, if you're listening, I'd love to see some stand-alone teen books from you). But when all you put in is hook, hook, hook and never bother to conclude, I start to lose my faith in you.

So I have to ask this. As a reader, am I being selfish? Is it acceptable for an author to give you a set of books that are probably never going to conclude? Or is it because I am spoilt by the huge number of books in the teen market at the moment?