Companies have to vigorously protect their intellectual property and copyright of source regardless. If they fail in one instance to assert those then it can badly impact them when it matters.
This is false in the United States. Failure to assert copyright does not relinquish it. Trademark does, however, because it is connected to brand recognition concepts.
Reminds me of a CEO I used to work for who realized that old blog articles (which no-one was reading anyway) were copyrighted of the years they were written, and made a fuss that "no-one is paying attention, these details are important for our image, we need to show that we're up to date". There was no explaining him that this is not how copyright works, what's important was that we remind people of the current year.
