[ugh]

Does the pettiness solve a problem with our communication? I would argue that it doesn't. I would be very surprised if anyone was actually confused by this or other similar articles. This is not even so much a problem with preciseness. All those articles say, in so many words, that they are talking about 'planets that don't orbit stars'. They amend the definition right there and then, problem solved.

This is a common way of describing things. Something is described in terms of something else, the properties that are different are pointed out separately. One might describe an e-book in terms of a book made of paper, pointing out, along the way, the important differences. Since e-books and books made of paper are very similar nobody would protest if, in that context (and after the explanation of the differences), the naked word 'book' would be used to refer to e-books.