I don't know on the D3 thing... seems a popular past time to bash id/Carmack. I didn't enjoy D3 much (as I am a picky FPS gamer), but I know a lot of typical people who really liked it. My dad, for one, loved it. Why? Because it was very similar to traditional Doom, just new graphics. He dislikes how FPS have gone away from twitch/scary/mindless shooters and just liked the pick up, shoot everything approach. Basically retro gaming with updated graphics. As Doom is a huge IP and aims to please a vast gamut of gamers it is not surprising that more hardcore gamers would be turned off. There are a lot of very, very popular games because they appeal to the likes of many on a casual level but are a big let down to those looking for more, better, and greater in regards to genre development.
I won't argue that Doom 3 is the pinnicle of FPS gaming by any means, but it isn't as bad IMO as many make it out to be. It is a scary (to many), visceral shooter with (at the time) technically excellent graphics. It is also polished in many ways, whereas many lesser FPS try to do more but achieve less. It ain't HL2, Farcry, Fear, etc... but for a twitch, mindless shooter (vintage DOOM) it executes really well.
While I and many would have liked a more modern Doom in regards to gameplay (and not just upgraded graphics) I know a lot of people who liked the "Just Play DOOM (TM)" approach and felt a lot of nastolgia.
Like many games, it comes down to what you come into the game wanting and expecting.
Of course in the bigger picture the question is: How important are graphics to a game? For games relying on immersion and have gameplay that leans heavily on graphical techniques it is important. Of course you can have great graphics and a great core game, but for a game looking for a specific experience and lacking the graphical umpf to deliver it can destroy the execution/impression. Hind sight is always 20/20 as games that take such approach are always easier to spot for what they were: immersive experiences for their time, but fall flat on modern gamers. Of course many gamers pay for the first 20 or so hours, not thousands of hours or how a game will hold up 4 years later. I can think of a number of great older games that the poor graphics destroy the experience now but were great for their time (most of the old football games are unbearable, regardless of the gameplay value).
