the possibility that someone would commit suicide because their organs can take care of their family and they can't.

I wouldn't classify that as abuse, but I can see how some would.

Two possibilities:

a) someone rationally chooses such an action because they have no better options.

b) someone is mentally ill, depressed, etc. and drastically undervalues the future worth of their life.

I would consider the fact that a) can happen to be indicative of something fundamentally broken in the society in which it occurs -- there should be better options. Of course, simply disallowing the deal doesn't necessarily address that, merely sweeps it under the rug.

I would consider b) abuse. I consider paternalism to carry with it an intrinsic evil, but there are greater evils, and the loss of a human life because of a potentially temporary confusion is one of them