Most people affected by this needn't go anywhere, and should be able to stay in their own homes, albeit around £1,000 a year worse off. Yes, this is a huge sum of money at the level of most people on benefits. No, this case is not going to be repeated at any major level up and down the country. For many there will be just about enough room to cope with the hit, and for many of the others a contingency fund is in place. The law may well need to be thought through better, though, as this is only a temporary measure. Housing benefit is due to be replaced in 2017 by Universal Credit, and an informed source suggests that there aren't yet plans for the same sort of "discretionary payments" when UC takes over.
This is the reason why it is not rational, because there was a known and available alternative. As I say, from experience I know that you often do not consider such alternatives when suffering from mental health issues, so I can say with a great deal of confidence that this was not the only thing that bothered this woman.
Without your going into details of what specific scenarios you'd want to die in, Sharingan, I'm certainly not going to judge your mental health! I hope they're all going to be pretty unlikely and extreme scenarios, though...