There must surely come a point where the greatest living Evertonian and his mates accept that they're not going to make a 400% profit on an investment they've added nothing to.
They paid £20m for 68% of the club, their shares are probably now worth about 500% of what they paid for them. And only going to go up so long as the club remains in the PL. There really is very little incentive for them to invest any more of their own money - it adds risk and will not return much more than they get for doing nothing