It´s not about liberals. Conservatives do it as well and use the NAXALT- priciple more openly, because they´re obviously in greater danger of being labelled as "rayciss".
Confronted with your example, they would answer that 15% of group B, are still a tiny minority, that doesn´t justify drastic measures.
Conservatives openly defend the kike double standards in Israel. They argue, that Jews went trough so many hardships, that they deserve a state which explicitly protects their ethnic lineage. Since whites have never been systematically opressed, pogromed and turned into soap, we don´t deserve an ethno-state.
So I take "logic" with a grain of salt and claim it is one of the most harmful white characteristics. Sure it is better to turn the other cheek, but it enables subhumans to cross the line habitually.
A white mob, instead of "objective" and "logical" white cucks (from all politcal spectrums) could´ve probably saved the American future, especially in 1965. Or 2014 in Berlin, when the "refugee crisis" began.