Nothing, Milo, in as far as it's not merely a cover for a dangerous and cancerous xenophobia,
I think it is rather unfair to cast Hungary's policy of avoiding to have her homeland flooded with culturally and ethnically totally incompatible people and faux refugees as "dangerous and cancerous xenophobia".
It is well known since the mid 1800s by European & American missionaries in Mesopotamia, Persia, Palestine etc, that those nations (dictionaries then referred them as 'races') will never never adapt to the western style of life, religion, philosophy and 'weltanschauung'.
Even the purposely blind and ignorant German government admitted at disillusioned long last, that the human experiment of trying to blend incompatible nations - that unabashedly und proudly state their unwillingness to assimilate - was an expensive, disappointing flop.
Indeed, most sovereign states resent, even modest dilution of their ethnic population with incompatible nations | ethnicities.
That goal, preserving Hungary's identity, ethnicity, seems to be her courageous, clearly stated, wise, long term policy.
Hence no rational grounds to pillorize her for a vision and policy, that most states openly or obliquely also pursue in one form or other.
Yes , injecting new blood into a gene pool is always beneficial. But in good measures.
And yes, Hungary's sleeping in the same bed with the Russian bear, is a lamentable price for her asperations.