If you keep reading it gives a reason why this is a requirement. Now whether you agree with the doctors or not is up to you but there is at least a reason for this.

But doctors say that people with severe liver disease from alcohol use may need more than just a partial living liver donation to thrive.

"The sicker someone is, the more they benefit from getting an entire liver from a deceased donor, as opposed to part of the liver from a living donor," said Dr. Saumya Jayakumar, a liver specialist in Edmonton and an Associate Professor in the Faculty of Medicine & Dentistry at the University of Alberta.

"On the off chance their (living) liver doesn't work, they urgently get listed for a deceased donor," said Jayakumar. "We need to make sure that everyone who is a candidate for a living donor is also a candidate for a donor graft as well, " she added.

From this, the reasoning appear to be this: there is a high risk that the living liver transplant will not take. In this case the patient may be at risk of dying instantly and thus need another liver transplant. Since the candidate doesn't not qualify for this other transplant, in the case where the transplant does not take, the patient will die instantly. This is in contrast with the patient being terminally ill however given time to live out the remainder of their life.

As someone else already pointed out, if the transplant from the living donor failed or had complications, now you have two people that need livers. It puts a healthy person at risk for a very low chance of a positive outcome. If they were paying out of their own pocket, then I'd say sure, go ahead, blow your own money on it, risk your own life and health. But they aren't.

Question: are there any countries where this is allowed? Would they have been able to go abroad and do this operation?