[anigbrowl]

Why can't I choose how I moderate spam?

Well, you can run your own mailserver and likewise some sort of social stream. But it's not so much about what you can or can't do, as the much larger number of people who can't or don't want to run their own communications infrastructure but also don't want to be inundated with spam.

Consider the parallel of robocalls, ie phone spam. People regularly complain to their phone provider and/or the FTC about being deluged with unwanted calls, many of which are scams.