There is no way you will ever be blacklisted from yorkietalk for having a "mutt"!! I think everyone here loves all dogs an can appreciate all the differences. We just happen to love yorkies a little more!
As for the "mutt" issue, it seems to me that mutts are actually quite fashionable nowadays. Doesn't Jessica Simpson have a mix breed. I can't remember, maybe a malti-poo?
Celebrate your dog, no matter what their pure-ness status is!