That could be a valid argument, IF this Vodafone app store was indeed "to fill in the European gaps where Google hasn't yet launched the official Android app store" -- as the summary says.
But that's false. According to TFA, ALL of the countries targeted by Vodafone are ALREADY supported by Google Market. That is (from TFA): The Netherlands, Germany, Greece, Italy, Ireland, Portugal, Spain and the UK.
Android apps can be downloaded in an executable format, just like desktop apps. So why the need for an app store?
Answer: Every good MBA is salivating at the thought of owning the eyeballs, billing, becoming the search engine, and slapping their brand on top of other people's apps. Remember the early days of the web when a gazillion "portal" sites tried to copycat Yahoo? It's the same situation here, a land grab of wannabe Apple iTunes imitators. To them, it doesn't matter that they are late to the party -- they propose some incremental benefit over Google's store and try to get everybody to come to the party at their house.
The actual innovators in mobile are the app developers, who are flat-out competing on ingenuity in a very difficult marketplace. Yet these overlapping app stores are trying to pit developer against developer in an attempt to control the market. It's a classic divide and conquer strategy, and the big loser is the user.