One big problem with "taxation is theft" is that you assume entitlement of all society's structure that you benefit from every damn day. Not saying it's perfect or even very efficient.
How does "taxation is theft" assume entitlement of all society's structure? If you have your money stolen from you, but they buy you something, that makes their theft ok?
The roads, sewers, electricity, infrastructure to keep it all running etc. etc. - all stuff you used to make that money *in the first place*. Could you have made that money w/o it?