I find it highly immoral how the major points of describing a DF are exactly what gnomoria is. My problem is the developing team is trying to make money out of it without paying royaltys to toady. I havent played it but a look through pictures and descriptions says to me that it is a rip-off and credit needs to go where credit is due. I understand the arguement that it helps DF's popularity. BUT the purpose of the game are not to do so. The purpose is to make money and that is where I draw the line.
The US courts have determined that you can copyright the art work of a game and the source code but you can't copyright the rules of a game. In fact, it is 100% legal to make a copy of the board game Monopoly by Hasboro as long as you change the artwork, rename everything different names, and use different game pieces.
In that respect is good because otherwise we would have seen Nintendo sue any platformer game simply because it had the same ruleset as Mario Bros.
In fact someone could make an ASCII game of DF as long as they used their own source code and it would still be legal.