The prison is located in Styria and not Syria as mentioned in the question. Syria is actually quite far from Austria.
There isn't much information about why this prison complex is a sprawling 5-star hotel but the two inscriptions on the prison perimeter somewhat sum up as to why prisoners are given such a nice treatment. This prison was made this way to mainly act as a model for others and to show the world that prisoners are normal human beings like us and they also have a right to be free like us and not forced to stay in a 8x10 room.
One of the inscriptions on the perimeter reads: "All human beings are born free and equal in dignity and rights." This has been taken from the International Covenant on Civil and Political Rights.
I understand that a lot of money was spent on this prison complex and that there isn't any need to offer so much comfort to criminals. I was wrong. I once read somewhere that if a child does something wrong, the parent shouldn't hit or reprimand the child. He/she should talk to the child calmly and explain to him in a polite way. That works wonders.
This prison sort of follows this by allowing the prisoners to become better human beings after they have completed their term.