Notch has stated that he originally wanted a game like Dwarf Fortress in tone before he stumbled upon Infiniminer[1]. I think you are right in that it's more correct to say Minecraft is a clone and evolution of Infiniminer, but was heavily inspired by Dwarf Fortress.

  [1]: http://arstechnica.com/gaming/2010/09/building-a-hit-one-block-at-a-time-the-creation-of-minecraft/

Oh definitely. I didn't really mean to say it wasn't, even if it sounded a bit like it.