I've had an argument similar to yours @hareball. Apple's developer programs were $500/yr or $3500/yr prior to the iOS dev program. Without that barrier to entry you get a lot more crudware and it devalues the whole store. It's not just Apple's store that has that problem, of course. But the other app stores pretty much followed Apple's lead when they saw how successful they were. I saw one store, not sure if it was Nook's or a different one, and they even had review guidelines that were almost verbatim Apple's right down the "apps can't be used to drive cars, trucks and airplanes" clause.
To put the visibility issue in perspective, there were over 800,000 apps in the App Store as of the end of January. On a given visit to the App Store, how many of those apps do you even see in a memorable way, and how many of those are ones that you didn't already know about? Think of a ballpark number.
Now think about that number compared to the 800,000+ apps in there, most of which you'll never look at or come across to purchase if you don't hear about them outside of the store.
I agree that visibility matters very little if your app sucks, but in that 800,000+, there are surely thousands that don't.
The sad thing is that Apple really could help apps get more visibility, but they just don't care. They make money either way.