The various comments along the line of "You can't blame him for staying and taking the money, the club is at fault for offering the contract" all have a degree of merit to them. If he was to agree to leave now he'd be losing out on a lot of cash, and it's clearly only cash that matters to him.
However...
I have worked in an organisation with an employee in a very similar situation. Woefully inadequate for the role for which he was recruited, stubbornly sitting there and continuing to take the salary whilst failing on a daily basis and letting colleagues down repeatedly in the process. He, like Tosun, was recruited directly by the company owner and inexplicably left in the role despite others openly complaining about his utter ineptitude. The owner, however, would not take the blow to his own ego that would come with firing the employee in question.
The workplace became utterly toxic. Other colleagues became demoralised that someone was being given a free pass to come in every day, do bugger all and get paid a very senior salary for it. Capable, high-achieving employees lost motivation and some left for other employees whilst others stagnated and became less productive.
It was a delight to leave that company and several ex-employees openly celebrated when word got round that the chap in question had finally been fired after more than two years of stealing a living.