Umm, no. My Z takes pretty good photos. Of course very low light situations will result in longer shutter time, and increased chances for blur due to camera or the subject moving. But in most conditions good photos are very possible, and mostly a matter of technique and experience. Manually adjusting ISO, white balance, taking advantage of what light is present, and bracing the camera can all have major impact on the quality of the photo, even in lower light situations. Moral of the story your problem is likely more the user, and not the equipment. I don't mean that in a pejorative way. But while not the best camera phone around, good photos are possible with the Z, with the proper technique.
I have no "problems" with photographic "technique"
Maybe my ideas of 'clear' and 'sharp' digital images is a little more informed and nuanced than yours. But compared to a few other 5mp phone cameras IMHO the Desire Z is on average at best and poor if you want to be critical.