It is sad that actions like this don't even surprise people anymore. Perhaps this is one of those Twitter actions that falls under the umbrella of "improving community discussions" instead of the first amendment.
A person can say what they want but no-one is forced to listen to it or help promote it.
As well, if this account was part of a system of bots and fake accounts that were spreading a particular message isn't that something that you want to see removed from a social media platform?
Isn't authentic information and material important?