It's unfortunate that the typical web development experience forces application developers to shoulder most of the burden of assembling and release engineering their stack. Quite different from building against iOS, or Win32, or Android. That's too bad: it's a big time investment, and it limits the set of people who can build and maintain a real application in production to those who've learned a surprising amount of releng.

Imagine how different the Linux ecosystem would be without distributions. The individual modules don't all have to come from the same place. But I think the OP's point about curation is spot on.