I have no idea whether nefarious means were employed to make it so popular, or it just took off like convenience store flashmobs and the knockout game among young idiots. Either way, it’s success spawned gamejams devoted to it’s basic principles, and had developers both large and small push out clones that replicated the gameplay exactly.
And in this, people went crazy. I dislike clones as much as the next guy, but my thoughts then remain what they are now: I don't know which emotion is stronger: frustration at the mania to clone something popular without adding anything new, or satisfaction in the fact that me putting out an app with personality will automatically set it apart. Make no mistake, I'd rather feel neither, but the latter is much stronger than the former.
In this, I don’t think clones stifle innovation. In fact, they allow new ideas and interesting games to rise to the surface of a app store ocean chock full of derivative sealife eating each other in a constant loop. I’m mixing metaphors, but the current mobile (and to a degree, console/desktop) gaming landscape is similar to the NFL. Every single dev team is so risk averse that the same 7 games get made with interchangeable graphics and different music.
Then, when someone implements the Wildcat formation of innovation (be it a fascinating premise, an engrossing story, new gameplay ideas, or a really REALLY cool pixelart main character) people praise them as a genius and everyone’s face gets melted off because the competition was so stagnant that the slightest change is seen as a triumph. Now all I need is a really cool pixelart main character...