But all this points also apply to the N9, it was a fully fleshed Linux system and arguably qt for writing apps was significantly more comfortable for developers than the custom framework based on gtk. I even recall that it was quite straight forward to port desktop apps, with very minor adjustments.

On top of that it was actually usable for normal users which the n900 failed at, largely due to not being usable in many networks due to the radio IIRC. The UI of the N9 was also much more polished. So unless you never used an N9 I don't understand how you would prefer the N900 (except for the keyboard).