Sure, morally it's wrong. But legally? That's a different kettle of fish altogether.
Ideas are not effectively copyrightable. For instance, hulmey's assertion that mibi 'stole' his d-day idea is patently laughable. But even if, say, hulmey had a great idea for a d-day map, had it all sketched out and everything (which didn't happen, mind, just laying out a concept here), all mibi would have to do is change some of the particulars (i.e. move it from utah to omaha beach, add battleships, etc.) to make it effectively 'his'.
When it comes to finished products like rj's italy map, the copyright concept becomes murkier still. I have some experience in this, being a small cog in the entertainment industry. The basic rule of thumb is that you need to change 30-40% of something to make it yours. How it happens in practice can be infuriating: I have a friend that wrote a spec script (essentially, an unpaid-for trial script) for a popular TV crime show. The contact he had at that show loved the script, but never committed to actually buying it. Then a month later, a different popular TV crime show aired an episode that was basically the same exact story, just with names and a couple of particulars changed. Unfortunately, my friend was shit out of luck.
Does the GD map substantially alter enough of rj's map for it to be its own entity? Maybe... there are color and gameplay changes, and when you add to the fact that it's a map of a real extant country, I doubt there's much that can be done in a legal sense. It might be different with a concept created from whole cloth like 8 thoughts, but even then, all the GD guy would have to do is change 8 thoughts graphics and call it 8 virtues or something.
Solution? I doubt there is one. The interwebs are full of dipshits like this. The sad thing is that he would've been better off just emailing rj and asking to use the map. It would've looked better and GD guy wouldn't have had to spend time altering it. Pressuring the guy thru the GD forums probably won't work either, as he has no reason to go light on the ban-hammer.
I feel for you, rj. As a creative type in a totally different medium, I know how much it sucks when you put a bunch of work into something and then see some fucking tosser rip it off. I suggest cultivating an air of smug self-satisfaction, that's what gets me through the days.