The terrible product (N97) was bad, but the after sales really nailed their coffin shut.
Obviously there were things the N97 could never do, so no firmware update would ever give it multitouch or anything like that, but basic faults like a GPS which couldn't hold a lock at more than walking speed when Nokia were giving away free turn by turn satnav was just ridiculous.
Delays in firmware updates as Nokia let carriers decide when/if their customers were allowed updates just left people stuck with old firmware, and old bugs that were fixed months ago. Not that Joe Public knew any of this, he just knew his Nokia was a lemon and bought something else next time round.
The latter issue could be worked round by changing the model ID of the phone to a generic Euro one, guess what, you couldn't mention this to anyone suffering a problem which was already fixed on the Nokia forums! If you did one of the pocket Hitler mods would pull the post and tell you off. I even tried to explain that if Joe Public thinks his Nokia is crap he won't buy one next time, and eventually you won't have anyone to moderate in the forum, but have to give up in the face stubborn stupidity.
After over 10 years of loyal Nokia (and Symbian) ownership I finally jumped last month. I was so fed up with my N97 which I'm still stuck in a contract for, I went out and paid real money for an Android based HTC Desire Z, and do you know what, it's fan-bloody-tastic! I've had it for a month and it's just worked, perfectly, no weird errors, loads of great free apps. I've even got round to starting to write some apps for it, something I did try to do with Symbian a couple of times, but on both occasions the development environment wouldn't even compile their own example code, so I gave up on that idea!
As you say, Nokia's navigation of their randomly changing road map would make for a good depressing film, but I doubt anyone would believe it!