[evgen]

The simple answer is that because whack-a-mole works to a limited extent, and when you run out of options it is worth the effort. Yes, there are alternate paths for users to take, but by eliminating the easiest or most well-known addresses you raise the bar for some users and add friction into the process. Putting up a new site takes a few hours, but getting the word out and dealing with the inevitable rise of malware/adware/ppc-stuffed bottom-feeding clones that will try to use this event to harvest victims will end up creating fear, uncertainty, and doubt among casual users. Sometimes this is good enough for the powers that be.