Its not why couldn't they, its 'why would they'? If they took control of Liverpool, which I understand to be the desired 'end game' (correct me if this is not the case), then without millionaire external backing, how on earth would you make the club prosper if you go up against Sky, and essentially bite the hand that feeds you. For all Sky's faults, they have ploughed money into the game, money that the clubs couldnt survive without. To achieve your ultimate aim of controlling Liverpool, and then taking on Sky once youre there, would be folly in the extreme.