I guess one of the reasons is lack of good design: the iphones are simply well made in this regard. The other, and that might even be more important: for many, and to simply slip the fone into your pocket, it is just too heavy/clunky. I know this from personal conversation: someone wanting a fone like this, not mainstream, open and versatile, but the size/weight is the showstopper. I find this rather sad, cause at current prices the N900 are a great bargain.