It's what's called "Barrier of entry", ladies and gentleman.. If a person\company pioneers some sort of new venture, and they don't slack off to keep building up on their product\technologies, then it's the distance the new competitors have to catch up to them.

Fortunately this isn't an insurmountable obstacle for Maemo, but still it's a rather formidable one given iTunes Store's significant marketshare in digital content market.