Just because it's possible to steal something, you/society should allow it to happen? Did I misinterpret what you said, or is this what you're saying?
> Just because it's possible to steal something, you/society should allow it to happen?
A closer comparison would be: you heard me tell a story. You don't think society should allow you to tell it to someone else because I 'own' it, and to tell someone else is to 'steal' from me.
You can spend your life arguing over who copied whom and by how much - or you can accept the flattery, get on and do the next thing.
Regards your second sentence, that is what I'm saying. A large company that's put lots of resources into something fighting of another company who "stolen" their idea, while tedious, makes some sense. For an individual, I can't see how it's worth the time, stress or money to worry about copyright.