This is partially a rant; you have been warned!
I do not hate ignorance: there are simply too many things in the world to not be ignorant of something. I cannot stand ignorance and pertinaciousness together.
It happend to me to work with people who sold themself like stellar programmers, yet they had never used a VCS. Being told to study the available documentation about a given VCS, they started to work on the assigned projects right away, trusting in their ego and the help of their preferred IDE, only to fail miserably after having committed log and temporary files, assets generated and maipulated at runtime by the application, their personal IDE’s project settings and having reached a point where the VCS itself could not tell apart a working directory from the recycle bin and the repository did not work properly. I have never been able to reproduce that mess and still do not know how they could achive those “wonderful” results. Being tasked with fixing corrupted working directories and wrecked repositories is not really funny, but it is definitely too much when you know everything could have been avoided just by spending a couple of hours studying some very basic docs.
My first contact with Git was a bit more traumatic: I do not remember what I started reading, but I thought “What the heck is all this?!?”. I threw everything away but returned to it after a while, only to be shocked again; the story repeated itself a couple of time before I saw the “light”. Now I use Git everywhere for everything and also installed and maitained an instance of Gitosis to watch over a couple of Git repositories at work for a while; then I realized that if Subversion had not been understood well enough to use it in a basic, straitforward way, Git would have caused way too many troubles.
Others have written about why Subversion should stay alive, but I do not care too much about things like enterprise penetration; Git and the other DVCSs are so flexible, provide sofisticated ways to handle and rearrange source code and add the complexity of decentralization on top of it. My experience tells me some people just cannot start to use Git as their first VCS (and some should not use it at all), but I do not think it to be Git’s fault: when people do not want to learn, you cannot give them enough rope to hang themself without seeing them strung up after a short while.
For this single, simple, selfish reason, I say that Subversion must live and prosper.