Since they want the flavor of their coffee to be the same for everyone every time, they roast it dark. As others have noted, light roasts are prefered by many because it preserves the nuanced flavors of the beans which is where you get all the descriptors of chocolate and berries and nutmeg, etc. I agree that dark roasted beans taste like dark roasted beans.
That's exactly right. I don't know if you've ever been around coffee when it's actually being roasted, but there are distinct phases it goes through as it gets near the end of the roast. First Crack, where it rapidly expands similar to popcorn, then second crack where the bean structure itself is starting to burn, and it sounds more like breaking a bunch of small twigs.
For me, I like it shortly after the last of the First Crack, which is pretty light. Others like it well into second crack, which can get really dark and oily. The difference may only be about 45 seconds between perfection and 1/2 lb of coffee for my daughter's boyfriend.