I wouldn't call it stealing users. I mean if you knew the people from reddit and they asked you and you agreed then that's one thing. But in a true situation of a site being taken down this is exactly what happens. People go elsewhere. What would happen if reddit was taken down for real? Would you do the same thing and for how long?
What you are saying in a way is that a company or organization's competitor (if you want to call it that) can do something by free choice and decision, then you have to do something as well or you may be viewed as doing the wrong thing and viewed as doing something not politically correct.