[avian]

I agree with the humidity argument, although even if you 10x the energy loss opening the fridge is still relatively small contribution to total energy use unless you open your fridge tens of times per day. It's nowhere close to what the article claims.

The defrost thing I guess depends on the fridge. Mine has two coils and the one in the 5 C non-freezer section generally stays above the freezing point when the compressor is not running. It does does not have a resistive heater.