The rationale, a not unreasonable one, is that cross-burning is not just the burning of the cross, it is historically and practically a threat of extreme violence. It was the threat which was ruled unprotected, not the burning of the two pieces of wood.
The burning of a flag carries no such history of a threat of violence, except possibly to those doing the burning. :)
I don't buy it. It was a political ruling. If I burn a Koran or a flag who is to know what the ‘real’ meaning of my message is? What about a confederate flag?? I file this with ‘hate’ crimes.
I never understood how the Federal government can outlaw certain speech in the private employer workplace based on offended feelings either, short a more restrictive consistent definition of the first amendment that only protects political speech(a Scalia type definition).
Thanks for the contrary view, always makes it more interesting :)