It's not our fault if you can't earn a living off the land rich men own

The rise of serfdom in Hungary was connected to the desire of rich people to be rich, which meant own landing and having serfs:

Stephen ordered that 'those who do not want to live under the authority of the monastery . . . shall be driven out of that place against their wish and their will.' Count Peter handed over one of his villages to the Abbey of Szazd with the condition that 'everyone who lays claim to status of freedom shall depart from there with the exception of the family (i.e., the serfs) of the church.' By the mid-11th century the kingdom was full of fugitive freemen, who posed a constant threat to public order.

Pal Engel, The Realm of St. Stephen p.78