To stick with your example you can just walk into any chemist in the UK & buy something to treat BV, you can also buy a lot of stronger painkillers without prescription here.
Really! I have the feeling it's the opposite in France.
For one thing all OTC drugs are kept behind the counter (even some cough drops!) and you have to ask the pharmacist for them. I think one of the reasons is that the pharmacist can answer questions and give advice. For example when selling plan B, my pharmacist systematically explains until when it's efficient and recommends thinking about switching to more permanent contraception and getting an STD test.
Also, a lot of the drugs that are OTC in the US are prescription only in France. They're trying to keep auto-medication as low as possible, and to replace stronger drug use (like antibiotics) by prevention work, because both are cost saving over the long run. I guess the fact that drugs are covered by social security only if you have a prescription encourages people to see their doctor! I think the only thing I've ever bought without a prescription is paracetamol.