I suspect that much of the disagreement here is due to players using different input methods. Someone who plays on a touchpad (like me) will likely experience far more misclicks due to the inherent inaccuracy of the device than someone else who plays with a mouse. Particularly since one of the goals of the devs is to release DD on pads and phones, it makes sense (to me) that pixel perfect precision is something to be avoided, not required.
But in any event, yes, DD is basically a puzzler. It's not a platformer, or an FPS, or a rhythm game, etc. As such, I have a hard time understanding the argument that misclicks are part of its "difficulty." There's a big difference between mistakenly thinking you can take out that level 8 Gorgon without using any potions, and accidentally clicking on that level 8 Gorgon when you meant to visit the shop right next to it. Devising a successful strategy and efficiently using your available resources is where DD's difficulty (is supposed to) come from, not hand-eye coordination.