I think you're overlooking the fact that all 36 million (or however many) people that visit Reddit each month are NOT equal....the active content creators are intrinsically more valuable to a community like reddit, simply because they make the community what it is.
When the people that make the content (of which 200k is no insignificant drop) that attracts the other 35 million ad-viewers are unhappy, Reddit MUST do something about, whether this 'minority' is vocal or not.