Low utilization because of poor personal information management (PIM) software results in low productivity. Software-wise, it's almost like carrying a shrunk laptop without good mobile applications. If you want/need to have a decent mini computer with internet connectivity and don't need good PIM software, N900 is for you. Also, if you like to develop your own software in a mobile environment, it's even better because many polished applications that can be seen in other platforms are still waiting to be developed for N900. I'm not saying that N900 doesn't have useful and well-written applications, but I'm saying that, because of a small user/developer base, there are not many choices when it comes to picking up the right applications for you. For some software categories, you may not find any applications that meet your expectations and needs, which means that it's your turn/fun to develop new applications.
When I was young, I was really interested in creating my own software as a hobby. However, having a real job, being the father of three children, and the husband of my wife, I don't have the luxury of spare time for devoting myself to developing new software overnight like before. Once I sit down and start writing code, I just cannot stop it until I have to because of outside factors that I have no control over. I also need to move forward in my career, so unless mobile development is my job, a strong desire for N900 development doesn't arise from inside me. I'd rather enjoy good usability and readiness of Android without worrying too much about lack of choices and quality.