Its not about mourning or having a lack of emotional composure. Its about common decency and respect for the deceased. Just because you didn't know your spinster Great Aunt Muriel personally doesn't mean you talk freely at her funeral about who gets all her money or how the only reason she never married is because she was so loose. I know the internet tends to be rather impersonal and this is a political forum in which all topics relating to politics will and can be discussed freely. However, it would be nice if people could just give it a rest until the funeral is over and the special election is announced just to show that we're all still human and not just mindless political hacks.
Or, at the very least, not hinting that the world is better off with the person dead.