In my view, Paula, this is your blog and you are entitled to shape it as you like. I do like the thought of it being a learning environment in which hate speech has no place. Now for the 'however' ...

From what I see in 'comments', all over the web, hate speech is not the worst kind of strategem that is used by people who want to push a particular point of view because it is easy to see it for what it is. There are far more insiduous methods that are employed. Of these, three are very common: inductive reasoning, erroneous cause/effect statements, and false syllogism. (There are many more - see Schopenhauer's 'The Art of Being Right' published in 1896. By the way, one of Schopenhauer's strategems is to quote higher authority.)
Are these strategems also not disruptive to the learning environment?

With regard to people who get hurt or offended by hate speech (and this is not an argument against you deleting it), I think a lot could be done to help them. It is not a matter of toughening-up, though that might be perceived as the outcome. Cognitive psychology, NLP, neuro-semantics and other fields all have approaches which help people to deal with hate speech and many other challenges of everyday life. These approaches are not difficult and are so fundamental to personal development that I believe they should be part of the basic educational curriculum.

With regards, GrahamJ