Don't call yourself dumb. You asked more thoughtful questions than had even occurred to me. I'm guessing here, but, it seems to me the reason the 'ecosystem' analogy is used so often is because it may be the most accurate. Maybe 'managed ecosystem' would be a more accurate descriptor. I'm not sure. I figure the majority of users of this site are in the same boat. We understand one or two pieces of the machine but aren't sure how they all fit together.
Cheers.