Other than "Cos I can", I struggle to see a narrative as to why the richest bloke on the planet would see value, (in relation to his wealth) in buying Newcastle anyrate.
I know you could say the same about many clubs, but like with us, the end game is obviously the ground/Liverpool Waters. Wolves is the agent links (and bought while in the championship). West Ham, the Olympic stadium.
I dont see the USP at Newcastle, in terms of turning a few hundred million quid into anything significantly more.
From a potential return on your investment, it makes more sense to buy Sunderland, and play a longer game.