What you're talking about goes well beyond the formal role of "designer". Consider, for example, what happens if you sign up with one of the many outsourced design firms. They won't do most of that. The good ones might do some user research. But that's not guaranteed; what they all promise to do is produce a very pretty document with a bunch photoshop mockups. Which an implementation team is expected to execute as written.
I definitely think developers should be active participants in all that work you describe. (I sure am.) Which is exactly why I encourage people not to have a formal "designer" role. If there's somebody who's officially responsible for X, then everybody else isn't. Design is a pervasive concern.
What you're talking about goes well beyond the formal role of "designer". Consider, for example, what happens if you sign up with one of the many outsourced design firms. They won't do most of that. The good ones might do some user research. But that's not guaranteed; what they all promise to do is produce a very pretty document with a bunch photoshop mockups. Which an implementation team is expected to execute as written.
I definitely think developers should be active participants in all that work you describe. (I sure am.) Which is exactly why I encourage people not to have a formal "designer" role. If there's somebody who's officially responsible for X, then everybody else isn't. Design is a pervasive concern.