Because the letters and numbers by themselves are not intellectual property. That's like banning a handgun because someone might use it for an unlawful purpose. The gun is an instrument...neither good nor bad. How it is used determines legality.
To use your examples, restraining use of the Hex code would be like KFC preventing anyone from using the word "chicken" or Coca-Cola claiming exclusive rights to the word "sugar" because the particular ingredients are part of the respective recipes.
Where does “intent” figure in? Your bank account number isn’t intellectual property, nor is your credit card number. But if someone released them on the internet for others to use to access “property” you didn’t want available, wouldn’t you feel there was a strong case to be made in keeping that information private?