Huh? I'm talking about basic phone features, they should understand very well what to provide, such as, contacts grouping, individual ringtone assignments, sms storing in folders, profiles, etc.

Nokia is well known of provide good phone functionality and easy to use even before Symbian, when they launched Symbian devices, they've make it better and better.

Suddenly, this Maemo is like totally from another company which have no experience with phones.

Fine, initially they don't provide it, I'm willing to give up my "hook" to those features. I've never been willing to change to other platform or devices, but N900 and Maemo is able to make me let go.
Sadly, until today, there is no improvements in these areas, despite it's by Nokia.

It may not be important, but similarly, it is not something that cannot be done. It's pretty disappointing that they neglected these phone features, and previous there was a post about an interview with someone from Nokia and more it's a disappointment to read.

All I can say is, don't be like Apple or Steve. If there no such features, admit it's the weakness, don't twist and turn and find excuses that it's not needed and so on.