Notice how all the games you mentioned had superior arcade versions? I've had this argument with sega fans before, if your console only had arcade ports then it doesn't have a good library because we now have access to the arcade versions.
Shoot we didn't even have to wait until emulation.... Once the NES was released many of those titles were re-released on it and they were vastly superior ports.
Your logic is all based on what you can do TODAY, not what you had back then. Atari was the best when it was the ONLY way you could play arcade games at home. Face it, as a kid you weren't going to go 3 years without playing games just because you wanted to wait for technology to get better (that you didn't even know was going to come out). You played at home on the Atari and when you could afford it you went to the arcade to play the "real" games. For some of us, going to the Arcade was a privilege we seldom had, so when we had the opportunity to play at home it was AWESOME. And yes, when something better came out YEARS LATER, you played that instead and the Atari became a dust collector. But that was YEARS later.
As for today, the way I see it, while some people that stick around here have a love for arcade games of old, MOST people either lose interest quickly in this hobby or are more interested in the building and restoring part than the actual game play. Twenty years from now there will still be some die hard World of Warcraft players who are building "retro" computers to play that outdated and ancient game. And some people who played it for a short time will dabble in it just to see if it recaptures what they felt when playing it when it first came out (before they lost interest and went on to the next big thing) before moving on to some other nostalgic idea.
Personally, I moved on from Atari and aside from the couple minutes of nostalgia I got when I fired up the emulator, I haven't had any interest in going back. But back then it was the coolest thing in the world and I loved playing for hours on end.
As for Intellivision, it isn't much different but I still spent dozens of hours playing D&D and Utopia on it.. LOVED those games. Are they the best in the genre (or title) now? No, but that isn't the point. At least not to me it isn't.