. Why is the consideration of a black hole as a 'cosmic vacuum cleaner' so wrong?
Far from the black hole, the gravitational field of a black hole is no different than that of a star having the same mass. Stars don't suck things in, although stuff hitting the surface will stick. Similarly, stuff getting near the event horizon of a black hole will fall in, but stuff on a trajectory whose closest approach is a few Schwarzschild radii will just zoom around like a comet.
I suppose because black holes don't draw everything in the universe into them, therefore they're not cosmic vacuum cleaners. Even if our own sun suddenly became a black hole none of the planets would be sucked into it because it would still have the same mass as the former sun.
