First, my measure is not the iPad mini, where on Earth did you get that?Old_Fogie_Late_Bloomer
The reality is, if Archos don't mess up the controls, this is going to sell. If your standard for success is "outsells the iPad mini", then sure, it's going to be a failure. On the other hand, if your standard for success is (more reasonably) "sells enough to turn a profit while serving a unique niche in the market", then it will succeed.
I was going to attempt a point-by-point rebuttal of your claims, but let's be honest, when you state that "Nintendo's handheld devices" are undergoing a "massive decline", you're clearly not letting any pesky "facts" get in the way of your "argument". The 3DS is doing fine. Obviously people want portable gaming devices. If the Gamepad 2 ends up being a decent portable gaming device, people will buy it.