Uhm, interesting topic...started out fairly confusing though.
So, well, Khazad...I don't think it's that difficult to make a clone of DF, since Toady did the difficult work already (putting things together and planning them to work as we know). So it could reach playable state within one or two years, less if having help. (As a coder myself, the hardest part is not the actual coding but the implementation of ideas in sane ways). With those ideas on the design board from the start, nothing stops Impaler from making a superior product with a better interface and ironing out DF's most obvious flaws.
However, what's with Impaler and that attitude of his? As someone else pointed out, if you like something, why badmouthing it at the same time? It's a concept so contradictory that I can't really understand the motives behind it.
Instead of paying loving homage to the game he should like...it kind of feels like a coldhearted shovelware bootleg cash-in. A game made without love is not worth playing as history can tell*. And DF has plenty of love included in the package. It's a game that shows the developer had fun making it, and we have fun with it because of that, despite the clumsy interface and the bugs.
Khazad won't bother anyone on its own, other than cause drama and fail.
And I am not saying that because Impaler behaved wrongly. His motives seem to not be the adequate ones to produce something like that in the right way. It doesn't even bring something meaningful/new to the table about design.
*Look back to the early 90's and the massive amount of cloned arcade/console space shooters. You can easily tell apart those made with "love" from those without. Wii/iPhone shovelware is a more modern example.