There isn't such a thing as owning a game digitally. If you have a game digitally, you are only ever renting it. You only have it until the platform owner decides you shouldn't have it anymore. That's the problem. That, and you can never go back and discover an old game on a platform that has terminated it's online services. Want to try some of those WiiWare titles? Good luck, you can't :D unless you find a console that has them already installed.
Besides, the price drop for digital games would have happened already, it didn't.