Why so adverse to wireless?
Part of it is there is usually (always?) an bookstore tied directly to the device. I know you can buy ebooks from other sources, especially if the reader does ePubs, but I'd rather not have any such direct connection to such a store. Mainly it's the principle of the matter, but it also makes it harder to accidentally buy more books than I can read (not having a tied-in bookstore, that is).
Also, with wireless capabilities often comes (somewhat limited) Internet access, which means being tempted to surf the web rather than read a book, which I do too much of anyway. (On my Nintedo DSi XL, and before that DSi, I spend more time using the browser than any of the many games I own.)