The thing is we only "get to know him" because of his online personalities exposed by the commenters.We do not have information on how he behaves in real life where we are bound by tacit social rules not to behave negatively. We are too quick to make negative judgement on him.

Let's be honest. We all harbour negative thoughts during our life. Which is why we express them on internet to get validation from other users on internet or get corrected by them which is a good thing. Is this wrong? Not necessarily. See, we are already bound by social rules not to behave unreasonably, where else can we seek places to vent our frustration?
The internet.

His mistake was that he used his main profile to express the derogatory statement. He does not know how impactful  the situation was until he decided to swiftly remove the comment
in order to reduce the tension built.

But the users WERE NOT even giving him a chance to remedy the situation. They took screenshot of it and posted everywhere. Their action of taking screenshot was worse than what he did to the late celebrity.

Let me emphasise, there were derogatory comments made by other users using their not-serious fake accounts and none of them were mentioned on news . Is his ignorance to seriousness of his comment proportioned to the treatment he received ? (his reputation is damaged, his career prospect too ,based on A REMOVED comment SCREENSHOTTED and FOCUSED by internet users)

Last but not least, has the victim's family made an official announcement of his distasteful comment? If not , it means that the matter was not worth to catch their attention. Remember that.

People should calm down. We did mistakes , we try to reduce the extent of the damage. This shouldn't be on news if those SJWs had not took a screenshot of the withdrawn comment and spread everywhere. Those SJWs are sharing the immoral things they did to him. Worse still they are too many to be marked down. Sad world really. Not everything deserve to be on hot news.