They both got rid because he was shit.
your Football knowledge is very limited.
They got rid because he fell out with several teammates(physical fights) and also had huge arguments with his managers.
Deschamps told him to find another club after a huge argument, but later changed his mind and wanted him stay at Marsielle. They were not going to sell him and told him he was going nowhere, but to get his move Newcastle he went on strike and claimed he was happy to go on strike for a whole season and miss a year of football if Marseille didn't let him move to Newcastle. Karma being a funny thing he actually missed 1 year and bit of football with a severely broken leg.
Marsielle were so reluctant to sell him that they only sanctioned him to move to Newcastle on loan with Newcastle paying loan fee of £2 million pounds, with Newcastle having the option to buy him if they paid an extra £5 million after he plays a certain number of games.