Rampant Games - Reminiscing Ultima

As the title says, Jay Barnson has been reminiscing the Ultima series, trying to express why it was so good:

DGM put the question to me. What made Ultima VII - still my favorite RPG - so awesome for me. My answer sucked. I listed some of the features that really struck me then --- and still do now. But the features alone didn't make the magic that I'd love to recapture. Much of it is probably just in my head (and in my equipped +2 Rose-Tinted Glasses of Nostalgia), but the question really made me think.