That's the thing: They may do it for trolling, but that doesn't make it any better. In fact, it makes it worse:

It shows that this guy is drowning in misogyny so much that he thinks death threats and rape threats are just a way to mock people. Complete and utter lack of empathy there that simply makes it stop mattering if he "believes every word he says" or "is just trolling".

End result is exactly the same.