I understand the feeling when a competitor pretty much photocopies what you did and tries to claim credit... But aren't we taking the whole ripping off thing a bit more personal than we should?
After all, most businesses are copies with just a minor differentiator - that ends up making all the difference.
Did you look at the screenshots in the linked post? They took the copy and the layout of the original site and did little more than to change the background color. To then state in interviews that their's is an original idea is plagiarism. If an author did this they would lose their credibility as an author and likely end up in a lawyer-on-lawyer situation that doesn't get sexy at any point. This isn't a minor differentiation in an otherwise obvious trade like plumbing or selling books, it is something else.
Look at it another way, if this were two video games, which would you buy and which would you take a dim view of? The one with the original dialog and voice acting and story-line, or the one that ripped it off?
After all, most businesses are copies with just a minor differentiator - that ends up making all the difference.