is it right to say that the crux of the judgement was about the portion of her inheritance from her dad, who wasn't able to express a preference to disinherit her
No, that is wrong. The recent judgement specifically ruled that out as a factor.
I kind of hope Helen I's current dire economic straits weren't part of the legal reasons for her to get the money
It may not sit right with you but that is the crux of the matter. As I've already explained the basis for the decision was that, in the view of the court, it was unreasonable for Mrs Ilott's mother to fail to make financial provision for her in her will given Mrs Ilott's dire financial situation.
By the way, her name is Heather, NOT Helen.
So the reason for the judgement is because it benefits HM-Treasury
No. Again, that didn't enter into it. Indeed, the amount awarded was designed, in part, to try to avoid reducing the level of benefits Mrs Ilott receives from the state (other than housing benefit).
I thought the 1975 Act applied if you were supporting a dependant
That is only one of the situations in which it applies. Spouses, co-habitants and children can claim even if they are not dependent on the deceased. Their claim will generally stand a better chance of success if they were dependent on the deceased but there is nothing in the Act that prevents a claim from a non-dependent adult child succeeding.
if you don't earn much and live on benefits poor diddiums we will force money from your dead parent but had you been in a stable employment on no benefits they we would not reward your endeavour
Ignoring the emotive language, it does not seem to me in any way unreasonable for the court to take the view that a parent has a greater duty to support a child who is struggling financially than one who is comfortable. Suggesting that this provides a perverse incentive seems to me to be very wide of the mark. The bulk of the settlement is to allow Mrs Ilott to buy her house from the housing association, thereby removing the need to pay rent (which is, in any event, met by housing benefit) and potentially allowing her to raise money through equity release in future. The cash left after the property has been purchased will give an income of around £331 per year. I really don't think this judgement will result in people choosing to live a life on benefits in the hope of getting a bigger inheritance from their parents.
Give it all away before you die
That doesn't work. If the court believes that you have given away (or sold cheaply) some or all of your estate in the 6 years before your death with the intention of preventing someone claiming under the Inheritance Act the court can order the recipient of the gifts to pay the claimant. So, even if Mrs Jackson (Mrs Ilott's mother) had given everything to charity before she died Mrs Ilott may still have been able to claim from the charities.