It is more a combination of the small and vocal user base and the message it sends to them about Google being open to cutting any product that has a usage they don't think is significant. Those people who see Google cut a product that they have adopted into a regular usage will probably add an asterisk to any recommendation for adopting a new Google product. There is no certainty that the lifespan of that Google is dedicated to that product. With the shutting down or Reader, it sends a clear message that almost no product of Google's is safe and that we should all be wary of what of theirs we adopt into daily usage.