SecretSooty, to a point I agree with you. HtoD came in at the time I got married and very welcome at a penny halpenny a mile. We had just moved in to remote quarters. The calculation was tricky however as normal hours route was through a back gate and out of hours was a longer route.
Later we moved and bought a house. Now this is where we disagree. My house was about 16 miles from the base; not through choice but through lack of choice. There were quarters from the same unit on our estate. Should I have got HtoD? I think so.
Later I was posted to another unit a further 15 miles away. Now the deal changed. I could have been paid for the house move (disturbance allowance) or I could continue to claim more HtoD. Without the sums the cash was probably not that different but the Air Force saved by not having to fork out the most dosh up front. Also Mrs PN who worked for the NHS 15 miles in the other direction would have had to leave her job or pay twice the motoring costs. HtoD while remaining in one's own home can help the Missus retain her job in the local area.
After a house move to a different part of the country I had 5 tours from the one house. The major driver now was MRs PNs flat refusal to move to Doncaster! Maybe in this instance HtoD may not have been appropriate but the system was happy to pay HtoD and also BSA. It almost made a 3 hour daily commute pleasant but thecar had to be serviced every 12 weeks.
PS HtoD is tax free as it is not seen as a perk but an economy. It is paid at a rate less than the 40/25 and you cannot claim tax relief on the difference unlike when you get the Public Transport rate.