I know plenty of people who are mad about it. Just because you don't post in the forums doesn't mean you don't know anything!
People are getting spolied with having to play a game forever and ever. A huge majority of all games end when they end, and mostly you can finish them within 24 hours. But you can't finish Fallout New Vegas within 24 hours (I mean every mission now), you put down hundreds of hours on maybe ten different characters to do everything a little bit different, to side with a different faction, focus more on talking your way out of situations than resort to violence, focus more on melee than on guns, finish a quest the evil way rather than the good way you did the last play through... and then in the end, after you've played the game seven times longer than it took for you to finish CoD, you've still probably haven't made it to the end yet (unless you're one of those that gives all side missions the finger, does the main quest right away and just EXPECTS there to be continuity after the
end of the game, just because
Bethesda do that in TES).
I don't think that I could be arsed do continue playing after the ending, because then I've been going on for just too long with one character. I can say I haven't reached the ending yet, and I'm going on with three characters already.
Then there's also jeopardizing the quality of the ending, either you have that [censored] ending that was in Fallout 3 (Fallout 1&2 style ending, my ASS...) which didn't change anything, and when you continued after that everything felt weird coz pretty much nothing had changed. Or you have the ending in Fallout New Vegas, which I yet have to come to, where you see the consequences of your actions, which characters you met and what you did to them, the faction you sided with etc etc, like in Fallout 1 and 2.