Maybe it would be better to work on improving the experiences of hospital birth rather than trying to convince more women to have a home birth?
I haven't seen this thread as being about trying to convince more women to have a home birth.
I have seen it more as partly answering the original question - why don't women have home births now which has led onto a debate about which is the safest place to have a baby?
In the 1950s women used to have homebirths partly because there was a good domiciliary midwifery service and partly because of a shortage of hospital beds. No doubt some women would have chosen to go to hospital but weren't able to. Then in 1970 the Peel Report stated: 'We consider that the resources of modern medicine should be available to all mothers and babies, and we think that sufficient facilities should be provided to allow for 100% hospital delivery. The greater safety of hospital confinement for mother and child justifies this objective.' At around the same time women started to be routinely booked into hospitals, with (from what I gather talking to older women) healthy doses of what Sheila Kitzinger called 'shroud waving' e.g. 'if you don't care for your baby..., a home birth baby is a dead baby' etc.
In 1980 Majorie Tew, a statistician, published some research to show that there was no evidence to back this statement up - she even found that the 'high risk' cases were safer at home. How her research all came about is interesting - she had set her students a task to analyse the statistics to showing why this policy of encouraging hospital births had come into being. When her students found that the statistics didn't show that hospital births were safer she didn't believe that they had done their analysis right and re-examined the stats herself, to find the same conclusion. She published her research and the debate has raged ever since.
The domicilliary service passed from Local Authority control to the health authorities in the mid seventies and who then realised that they didn't actually have to provide a homebirth service, making it difficult in some places to obtain a home birth. Where there are good homebirth services the take-up is high - the OP gives a link showing that in Porthcawl and Pyle, the rate for this was 25% to 30%. This may be a minority taste still, but it's a big majority.
Personally I think they took a wrong turning by concentrating on the place of birth and should have been concentrating on the appropriate quality of care for each woman. Hence the present mess in some places where one midwife is running between two or three women in strong labour, which I don't think is good for anyone - neither the labouring women, nor the midwife run ragged, but the bean counters seem to think it's 'efficient'. At the same time I think we should try to improving the experiences of hospital birth because that will be what a majority want - and I think it comes down to more than splashing some pretty wall paper about and putting a few bean bags and rocking chairs in the delivery suite. Again, I see staffing as the key factor.
(Whew, something of an essay - I am a social scientist who studied this issue at some length.)