Don't often comment on HN but have to point this out as a med student in the UK: the cost-benefit roughly works out for those in favour of giving the therapy when the alternative is a lifetime of coming to hospital 3 times a week for Factor IX infusions, and the additional cost of stays in hospital for bleeds/haemarthroses and the complications thereof. Of course, this also ignores the human cost, particularly the extra care/stress around avoiding cuts/bruises in every aspect of life. In this respect these gene therapies appear lifechanging for those who suffer from the disease. [1]
I will also say I know the team who wrote the guidelines for use of these therapies. I believe they were mostly finished before the infected blood scandal became a big story. Politics didn't come into it.
[1]: https://www.bbc.co.uk/news/articles/c4nnn51rdrzo