Because you never want a fridge or freeze plugged into a GFCI outlet or breaker. In fact, the code allows exceptions for this. The freezer in my garage is connected to a non-GFCI recepticle.
I am not disputing the code aspect of this statement, just adding that I've had a fridge and freezer plugged into a GFCI receptacle in the garage for 5 years continuous with no trips from them. I suspect the GFCI works because I've tripped it a few times from downstream outlets.
On the other hand, I wonder what it takes to trip an AFCI? I've got them on the bedroom circuits and like everyone else have heard about the nuisance trips. I've tried a few test cases that I thought would certainly trip the AFCI but have never been able to do it.