What if I don't want to be "flattered"? I don't really see anything flattering about someone copying one of my ideas when I don't want them to copy it.
You seem to be using a different definition to the word "flattery" than any I know. Being copied is inherently flattering whether you want them to copy you or not.
Flattery is a two-way act to me, why else did you use the word? You basically said "accept that someone copied you against your wishes and just ignore it".
I can see your point generally, but in this case, I can't see how being copied is anything other than flattering. It means the idea was good.
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.
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.