There are lots of forms of 'don't care'. Don't care because:

- they have limited resources and they are prioritising something else,

- there is little realistic chance of getting a conviction.

- it's not one of their politically set department targets

- they fundamentally don't think it should be illegal - say historic blasphemy laws still on the books.

Is your main concern resources or enforceability, lack of political focus or some combination of all of the above?