Well, then you can say "walking isn't free". Your shoe soles get worn down, you need "extra calories" for that too, and you need to buy extra clothes, an umbrella and a scarf to keep warm
Once again, the OP isn't asking for something that's not provided elsewhere. Many organisations provide bike mileage. The general dividing line is that where some form of mechanised transport is required, mileage is covered. So if you use public transport, a car or a bike for your journey you can claim mileage. Having a machine = expense. True, yes, if people are walking long distances that does produce wear and tear. The assumption is that if it's that long a walk, you'll use a machine. And claim mileage. (The umbrella, scarf etc are red herrings on your part. It's fairly normal to have those.)
Look, this is once a week, is it not? Not every day
It's 14.60 once a week and the payment is only for every other trip. If you're on £70 which is roughly what JSA is, that's 20% of your income gone on one journey.
True, the OP could, if the situation persists, move to a larger place nearer a job centre and jobs. In the last 20 years I've lived in four cities and have recently moved to a rural area, all for work. The last move I did on the cheap. I hired a friend with a horse box. Family helped me to pack and move. I still had to stump up a larger deposit than I'd previously had and that and other associated moving costs meant a loan. The loan repayments are spread over 3 years. The job contract I moved for? That's 2 years. That is the reality of the current job market.
Most of us, however comfortably off we are, do not have that great a safety net. Illness, relationship breakdowns and redundancies can all cut deep and have a nasty habit of occurring close together. JSA is a safety net. Just be glad you don't currently need it.