That is the point. Development would not stop. Bitcoin would not be stopped. It should not be feared. The success of Bitcoin does not depend on the Bitcoin.org development team.
The goal is true decentralization.
Might as well just explicitly declare the end of the bitcoind development project.
bitcoind is currently the only stable implementation of a full Bitcoin node AFAIK, so if the bitcoin.org project was closed everyone would move to some fork of bitcoind. Probably a fork maintained by the current developers of the bitcoin.org client. There wouldn't be much increase in "decentralization".
Here's the question: Would a unofficial, newly created forked have as great of a cloud of influence? Would it have the same authority Bitcoin.org has now?