Yeah, it took me weeks to get familiar with PS, but not years. Within a few weeks I was cranking out mocks that matched what I had in my head, it's just that what I had in my head wasn't very good.

Investing weeks in learning a new design tool should be unnecessary. We're good enough at software design that a tool could exist where a seasoned designer could open it up and intuitively start building a beautiful, functional prototype.

If there's a steep learning curve, a tool will never hit mainstream because most people won't invest the time to learning it.

If you can make something, however crude, quickly, then your interest will increase gradually over time because you have meaningful output.

If I can't take a tool and learn how to use it while still respecting my tight work deadlines, I'm probably not going to use that tool.

When you had just started learning about Photoshop, were you cranking out lush and detailed mockups? Or were they crude, and over the years you honed your skills to the point where they measured up to what you could imagine in your head?

Is there a point though that when you were first learning Photoshop you were learning more than just how to use Photoshop? There are a common set of concepts and interactions that can be immediately applied to most bitmap and even vector tools. The ramp up time for new tools is always going to lower for that reason.

I agree that learning curves shouldn't be dismissed as always bad. Look at any 3D software, the learning curve is huge. We have it so easy here in 2D land :) And having done 3D work in the past I would argue that the payoff is necessary and worth it.