Death, especially that of a child, has become more 'taboo' and unacceptable. I'm not sure why this has happened but probably due to improved (well, perhaps not so much recently) living conditions, longer general life expectancy, technological advancements, the culture of self-preservation, decrease in religion and beliefs in an afterlife and many other factors. People don't want to face it.
My grandmother had 13 children in the 1920s- 1940s. Only 6 survived beyond the toddler years and became adults. That wasn't uncommon, in poorer areas where religion and poverty had compounding effects. It's not as common, now. Firstly, people aren't having such large families (birth control) and there has not, here, since been a major war that has decimated the population. Improvements in medicine have raised expectations, often way beyond their practical application.
How would Archie's mum, should she 'win' her case, feel when all the media attention dies down and grim reality sets in? She would have a lifelong commitment to her severely disabled son and even the strongest person would at times feel utterly debilitated. Furthermore, has she thought about Archie's possible experience and what it would mean to him, even if he had very basic sentience? It IS heartbreaking but there is no way to bypass grief. Eventually, you have to go through it and the more 'baggage' (i.e. seeing him wasting away) that is acquired along the way will make memories all the more traumatic and painful.
Guilt might also be feeding into her lashing out at others. Wondering about the 'only ifs', knowing he had challenges and not always being to help him...who knows? It's a horrendous position to be in.