1. It's not a dedicated mixing service.  The coins do get mixed though, yes.
2. Because there are people who want to bring us down.  All I will add to that is big players in their earliest stages need to be careful what pool they mine in.  We don't have any reason to do anything differently than what we're doing.  No matter what anyone thinks they know, there is risk when you are in our shoes.

I shouldn't need to go into details again because this has been discussed, and arguing why we should stick to our methods will be a never ending battle.    Our priority is to protect this operation and to protect the customers.  Simple as that.