I wrote a forensic manual that simply HAD to have an "active" TOC for the book to be of any use and am quite happy with the way the ebook functions.
If you really wanted to write a book with a simple TOC that doesn't work as links to actual chapters you could certainly include it in the start of your book but I'd assume you'd also want the TOC.NCX too (as a linking TOC.)
With my book I wanted it to open at the Preface and certainly not at the TOC or metadata for that matter. I'll call it author (or self publisher's) preference. Having the TOC at the end of the book is also a bit of a "summary" for the reader to page through.