So now we can't patch a security hole in a library without "recompiling" every application it's linked to? That seems like a huge step backwards to me.
Mac and Windows applications ship bundled versions of third party libraries all the time. Managing a complex web of name+version based dependencies is much harder in a decentralized software ecosystem, so bundling starts to look attractive.
For our purposes, the benefit of a system where software is more reliable, predictable, and accountable is greater than the cost of asking developers to recompile in unusual circumstances.
This can instantly close the hole until a patch is released. This keeps users safe and gives application authors time to test against their application with the new library before re-publishing.
In many cases, application authors are the only people that are qualified to test interactions between their applications and the updated library.
During a distributed operation, participants can arrive at many different points in time. This means that applications using the newly-patched library will likely be interacting with applications using the unpatched library. Whenever multiple versions of anything are interacting with themselves things can get complicated.
In light of this, we opted to keep things simple and predictable for ourselves (and others). Since applications always run against exactly what you say they should, you're free to keep running forward, without having to worry about tripping over past decisions.