Loads of stuff in the UK is not set into law but rather into custom iirc. So instead of "because the law says so" they have a bunch of "because we've always done it this way".
Unfortunately we are fighting against that effect too. Thankfully it's not as effective over here. A lot of our customs and culture are deep rooted, historically. This makes it a lot harder to overturn, without creating problematic ripples. It's not stopping them trying however.
As the saying goes. In America, 200 years is old, in England, 200 miles is far. A lot of our customs have been shaken out and tested over the centuries. They still exist because they both work and are hard to dislodge. America's government is a lot younger, and was made as a whole. This leaves it a lot more brittle, and so easier to break.