Or I could be in favor of whatever it is, but don't want my news feed to be filled with my commentary about whatever social issue du jour it is like everyone else who engages in this, and would rather it just be more personal.

Also I don't want to have to be attacked or have to defend my position if I don't word things perfectly (more commonly don't show enough outrage, because I don't have as strong of opinions as a lot of people on social media), which seems to be a common occurrence nowadays.