Santosh -- you're right that it is not reasonable to speculate about the true "worth" of a system without having used it or having heard the general hands-on opinion. I guess the point is that a sensor of that size really does not need interchangeable lenses. Modern zoom designs are well capable of producing a center of the image circle well enough to cover that size with a sharp, distortion-free (and free from other abberations) image. And the lens does not have to be a prime to be fast enough -- Olympus has already done that with a collapsible zoom in the XZ-1 which is pocketable in the true sense.
I guess the question is not whether the camera is "good enough" for certain purposes. The real question is -- who is going to buy and use it and take advantage of the lens choices offered. In my mind -- I can't see any serious photographer I know of who would do that.
I have a soft spot for Pentax for many years. But honestly -- until I heard the trivia that the "K" mount stood for "King" and the new "Q" mount is supposed to represent the "Queen", I actually thought that "Q" stood for "Quixotic" (Pentax being Pentax, that kind of humor would not be entirely unexpected from them). In any case, looks like the king has a rather pint-sized queen.