Actually Ill take one more go at trying to simply it.
Lets say you own a store and sell widgets (anyone who knows econ is probably sick of dealing in widgets haha). And I own a store across the street that sells widgets. These two stores represent the app stores. Now I decide to go into your store and leave a bunch of fliers on your counter that say how my widgets are amazing, and it says all the cool new features my widgets have, blah blah blah. These fliers represent the app (stay with me). Are you people honestly saying that you would let me go into your store and leave a bunch of info about my product? Of course not, because its your store and you're trying to maximize your profit. So you throw out my fliers. This holds true whether its me putting the fliers there, or a third party (the app developer).
Now part two of the analogy. Think of the street as the internet. I don't own the street and you don't own the street, so its wrong for me to put a barricade down and prevent people from going into your store to check your widgets against mine. Because streets are public, I have to allow traffic to move about as it wishes. If people walk into my store great, but I surely can't stop them from walking into your store.
So to wrap it up. People need to stop confusing public and private. The apple app store is owned by apple. Radio stations, tv channels, newspapers, etc are also private. They decide what type of content they will carry. It is foolish for them to advertise for their competition. The internet however is public, and no one owns it, so to prevent users from accessing certain aspects of it is wrong.
To sum up yet again, put yourself in the position of a business owner, or one responsible for the performance of a business, then think what the appropriate strategy is. In addition, stop making analogies where you compare privately owned things to public goods. It does not work that way.