There's an existing issue of 2D art being difficult for many users. How would they cope with having to make full models for everything in their game, I wonder.
I actually find 2D a lot harder to do than 3D modeling. Even if you're not good at drawing, it's still possible for you to be good at 3D modeling.
Now if you're talking about high poly models meant for next-gen games, then you're right.
But why would Construct need high poly models in the first place?
In a 2.5D game, you could easily get away with using low poly models created in a tool such as Milkshape. Which by the way, are rather easy to make (see here for an example made in only 6 steps!).
I'd love to be able to use low poly animated 3D models in my 2D games someday. It would make things a hell of a lot easier and I'd be able to do some insane G-Gradius epic boss battle type stuff.
I really really hate drawing sprites. It's just something I absolutely cannot stand. I am just not able to visualize how things would look in 2D and just draw them like that. I like being able to rotate around and fix individual little details without having to go back and erase everything. Especially for animations. If you mess up a sprite animation, you have to go back and redraw entire frames of animation. Whereas in 3D, you can just fix it on the fly.
Plus rotating objects for things like huge battleships in shoot em up games are a bitch to animate. You hardly ever see objects rotate around their x-axis (roll axis) in 2D because it's such a pain to animate correctly. In 3D, however it's easy as simply rotating the model around.