Because it doesn't leave a chance for a dialog - "it's my way or a highway" and promotes national hatred while the whole world is trying to fix that situation. Do you want Russia to develop in the eyes of the world? Teach people some tolerance first.
Strange question, you don't want me to bring up Ukraine but at the same time want to fit my answer into the frame of current conflict with Ukraine.
Generally the censorship limits free will and I believe that's what you don't want.
You can read Galkovsky's LJ about the US and black people in power in the US, he's quite graphic about it.