(The following rambling message isn't to anyone in particular, I'm just annoyed at the casual calls for litigation, usage of the term "ripoff" and the tut-tutting of monetary gain in some posts above)
Toady gets paid thousands of dollars a year making DF, in donations. Just saying.
Toady may be one of the best game developers in the world, according to some measurements. He is certainly my favorite, trumping Notch in dedication and in a willingness to create depth. Notch is very cool as well, though he no longer personally heads up Minecraft development and is on to bigger and better things (0x10c). The dude making Gnomoria is also a cool dude. I'm glad we have so many cool game designers in a very similar genre-space. We'll have a proliferation of ideas and the DF-like market will swell.
Toady will always be my favorite developer, and I think he deserves to make millions in some way (commercialization, kickstarter, selling themed hats...) but he obviously is quite happy to take donations for right now, and has repeatedly seemed very supportive of all the new games popping up that are similar to DF. If he ever feels like he wants to make bank, he has a lot of options to do so.
My point is, just because Toady isn't building the gold-brick house that he could be (maybe he will in the future, if he wants), don't try to tell me/us that Gnomoria shouldn't be supported or liked because its developer *gasp* wants to make a living at his chosen profession. He's making a game a lot of people want to play (dumbed down DF with graphics), so he's obviously meeting a demand.
Also, your arguments calling for litigation due to some kind of copyright violations open up a huge ethical can of worms concerning intellectual property that I would hope we here at the Bay12 forums would rather just leave in the tackle box. If I'm wrong about that, awesome, let's do it.