This isn't the full postcode database. The full postcode database maps postcodes to actual addresses instead of co-ordinates. You could map these coordinates to addresses but you'd need Ordnance Survey data which you've also got to pay for.

Great... except you can't use the information legally and it will not be kept up-to-date which makes it useless

I can't believe we have to pay for the postcode data in the UK. It should be freely available

Why isn't it legal to use?

Even if I download and read a book illegally, I'm still allowed to post quotes from the book on my blog. I'm still allowed to know the material. Why is this list any different?