“Because you didn’t get caught the first time”
 
Although the context of this statement seems like it would work a lot better if it were uttered by rainbow dash.

Something that never changes, never gets better.

This has so many potential uses.

Because now we know that it gives you cancer 20 years later.

@northern haste  
True. I’ve just heard this logic being used to defend a lot of bothersome things.

Well, that’s an interesting question. You see, rules and regulations are not immutable, and are prone to changing in response to changing times, needs and contexts. In fact, it is commonly held that one sign of a well-made legal code is specifically it having an inbuilt system for facilitating and directing change of its prescriptions and regulations! A good example is the U.S. constitution itself – the original constitution that was ratified in 1788 was an altogether different beast from the one in place today. Among other things, the original version allowed the ownership and sale of slaves and the use of race or income to deny voting rights, which have been prohibited by amendments. Non-amendment bills and judicial rulings have also prohibited actions once freely allowed, such as how the once fairly common practice of denying employment or advancement on the basis of gender, sexuality, race and religion, among other factors, was prohibited by the Civil Rights Act of 1964.
 
Or, short version: rules change. That’s how rules work.

@Starry Mind  
This isn’t meant to apply to everything

I don’t know, OP.