The legal arguments are that these villages are built on state owned land. Some of the Bedouin just build wherever they like for convenience purposes whislt others feel they own land because of agreements reached with the Turks about 200 years before Israel came into existence. Today between them the state and the JNF own around 90% of the country and some agreements made with the Turkish Empire are not recognized by the state. ( new countries formed old imperial rules not recognized ). The villages are illegal because in all countries for a village, town, city to be legal it must be recognized by the authorities and if its not then its not legal. What would stop me going to the local park and building a few homes and saying its official a village ... countries have laws. Israel is a small country and the majority of the Negev is undeveloped and the government wants to change that and if they are going to do that they can't have bedouin villages built on land they want to assign for development. This isn't much more than a glorified compulsory purchase, things which happen al over the world. Its also not discrimination its the fact the Bedouin happen to be the people who happen to be occupying the land the government wants to reclaim. The local municipality wants to build a new road but your home is in the way they can legally obligate you to sell the property to them so it can be ripped down to make way for the road. Its also legal to forcibly remove people when a municipality makes a compulsory purchase because if the property owner won't leave then the police can be called to forcibly remove them so the bulldozers can come and do their job. With the Bedouin its exactly the same thing but on a larger scale. In the US the Indian reservations would one day have become inevitable. If it had been done 100 years later it would have been done in a nicer way but eventually the Indians would have moved to reservations because development cannot be stopped just because one group of people have always lived a nomadic lifestyle on vast areas of land. The world which is based on fairness and moral ideals is not the same as the real one and the real world is full of problems life is unfair sometimes.
from the article: Netanyahu's office promoting plan to relocate 30,000 Bedouin