Without knowing what actually happened at BER I cannot claim one way or the other, but AY buys ground handling services from some company, probably the cheapest one. If that company is unprepared to deice aircraft within a reasonable timeframe and if AY plans their schedules without allowing time for this, in a destination where the average temperature is 0.7 °C, then it very much sounds like a (bad?) commercial decision to me, made by AY, and is not really related to severe or abnormal weather or to BER airport being badly managed.