We can all make some mockups in an afternoon. It's not really worth telling everybody about unless you've done something, IMHO.
The fact of the matter is that there are a lot of people out there with lots of engineering ability and not much design ability who might jump at the chance of implementing something that's been thoroughly mocked and product-ed out.
It's like a programmer saying "Job's done" because they made a DB schema.
You are saying that a mockup is basically nothing, that anyone can do it. If that's true, why do we need designers at all?
Most of the time the only people I hear complaining about UI design are UI designers. Except for exceptionally bad cases, most people don't care too much what their applications look like.
And most people would rather have a working implementation with an ugly UI than a pretty picture/mockup that doesn't do anything.
If all the designer can do is mockups, then IMHO they are not doing their full job. Like I said in the other reply, it's like a programmer saying "I made the DB schema, what more do you want?"
Not even any explanation or justification of design choices. Just a sentence claiming it is 'self explanatory'.
And then there is the last sentence, which basically just means 'who wants to take my single concept image and do all of the remaining work?'