The web is not a carefully curated gallery of web pages and yet we're still able to find the good stuff all the time thanks to intermediaries of discovery
This is hardly a strong argument, as the main "intermediary of discovery" is Google, and most internet users are all too ready to give up their banking information to websites which have an official looking header on the page. Just because it worked for the web doesn't mean it'll work for Apple's AppStore.
So you'd like for the web to be put back in the box and replaced with an AOL Walled Garden of wonder? Freedom can indeed be dangerous, but I'd rather be free to hurt myself than smothered to dead by paternalism.
The existence of a restricted marketplace doesn't mean the greater internet must become just like it, as if through some kind of relative application of logic.
The internet--and the real world in general--can host a million restricted marketplaces, each designed for specific interests--and still be free in general.
Your reductio ad absurdum is suggesting that the presence of a gated community in the Hamptons means that every neighborhood ought to be gated.
I believe that forcefully weeding out the crap is detrimental. It's hard to define crap. If a buggy app provides functionality users consider critical, is it crap? Wouldn't it be better to let it evolve into not crap?
This is hardly a strong argument, as the main "intermediary of discovery" is Google, and most internet users are all too ready to give up their banking information to websites which have an official looking header on the page. Just because it worked for the web doesn't mean it'll work for Apple's AppStore.