Because "never admit Jew-haters" is not the actual governing doctrine in the EU
What the EU actually works with is a mix of universalist ideology, legalism, labor demand, and elite status signaling. Under such a framework, importing "people" like that is treated as an integration problem to be managed after they get there. Same reason why the EU can expand "asylum" and migration pathways while also running antisemitism strategies and education programs.
From the EU's point of view, there is no contradiction, because self-preservation was never the primary filter