to answer your question, yes without a doubt. even a basic user can pick up an n95, turn it on, and they can make calls with it, find the contacts, send a text message, etc. that's the whole point of s60 compared to windows mobile and other smartphone OS's. s60 bridges the gap between regular phones and smartphones. the menus, interface, input method, are all stolen right from a regular phone. but s60 can also multi task and install 3rd party apps. the only drawback is they would need to make the menu key HOME so its more self explanatory.
my related story: i sold my n75 to a friend who is clueless about phones. gave him the 20 minute tour, and he's only called a few times with questions. but he's smooth sailing now after only a day or so. and his questions were "how do i set mp3's to individual contacts." his last phone was a razr, and that's the only type of phone he's ever used. he also has no technical background or college degree, if that means anything.
where i agree with you is when dealing with anything that doesnt come with the phone out of the box. pull a new s60 phone out of the box, and its super easy for anyone to learn with a few pointers, i.e. long press for task manager. but adding apps, even google maps, is where it gets over people's head. like handy taskman is not an easy app to explain or have a new user obtain. but no doubt to use s60 with its out of box features is no brainer, anyone can do it.