Meteor tries to create an entire new ecosystem using Node's merits. The reference you posted lists pseudo reasons for choosing a new package system. I don't know if here is the right place to discuss them but some of them are heavily misleading and primarily business-driven and motivated by a developer's lock in. It's important to state that especially Node's npm is one of the most modern package managers around and already solving issues like repeatability, asset building and bundling (npm's concept is totally different though). Sure there's a need for package management on the client side but coupling everything together is not the answer.
I highly appreciate the talented team behind Meteor and their achievements up to now but it's sad and a deal breaker that they choose this non-npm route.
As a final point, I am aware that maybe it can be good to have competing JS on the server ecosystems and all JS users will benefit at the end from this competition.