I took up with a woman my parents don't care for. They disinherited me and left everything to my sister, who married wealthily and doesn't really need it.
Are there no failsafes against that in your country? In Germany, you can disinherit a relative only if the attempted to murder you. Under pretty much all other circumstances you'll be given a minimum inheritance, defined by the law.
I don't think of it as a failsafe. I think of it as Government intruding where they have no right. Whether I agree or not on the cause of disinheriting, the fact of the matter is, it is their stuff and they should be able to do what they please with it. The only caveat to that would be if there was some sort of duress applied or if there was dishonesty implied when they made out their will.
FWIW, I am expecting nothing as an inheritance from my parents. I expect my sister to get everything. It is an idea I have gotten used to and am now simply resigned to the fact. I just don't think the government should have the right to tell how they must disperse their stuff when they are gone.