Leauki, I liked your Sim City analogy. That's a good game. Interesting yet it couldn't hold my attention for long hours.
I bought Sim City 4 and then noticed, as with Civilisation 4 and some form of Worms, that wouldn't run without the game DVD in the drive and even then would run only in fullscreen.
Since I feel no reason to go look for the DVD whenever I want to play few minutes and do nothing else on my computer while I am playing, I never played it.
If I play slow games like Sim City or Civ without doing at least one other thing on the computer I get bored from information underload. I usually play a strategy game, watch a DVD or listen to a podcast, read Web articles, read newsgroups, and reply to emails all at the same time. It distracts me while I am working on a program.
But game vendors these days don't seem to get this style any more.