Safeguards are usually eroded away to become pretty meaningless as time goes on. Take for example the UK abortion laws.
A young David Steel made a very impassioned speech in the commons in the 60,s to convince them that it needed to be legalised in order to protect the small number of woman who were desperate enough to put their lives at risk in dangerous back street abortion clinics.
He won the debate and the law was changed.
20 years after that, despite all the advances in contraception, abortions were taking place in the hundreds of thousands per year.
Today, despite even further advances in contraception, very senior people in the medical profession are currently trying to change the law that a woman can choose to abort up to the point where she goes into labour, as that is her basic human right.
I doubt David Steel intended this to be the outcome, but thats how these things tend to end up, once the militant tendency of the particular protest issue gain influence.
Its not that big a stretch of the imagination to see a society in say 100 years time, where the only really elderly people are those who have plenty of money, and offspring who aren't desperate to get their grubby mits on it.
Going back to the case of my father. One member of the family (who systematically robbed him blind) would definitely have manipulated him into this course of action if the law allowed it.