My ex-girlfriends 6yo had one of the vtech kids cameras, and contrary to your evaluation, it was perfect. Kids can be rough and clumsy, so something of decent size was ideal, and I don't believe many 6yo are so discerning that a small LCD screen is of any concern. And that's before you get to the often fleeting attention spans for such things as cameras and other toys/gadgets. That said, all children like people are different, but it's not as black and white as rubbishing a basic kids camera as poor quality. Often that's more than enough.
VTech Kids recently sent me some of their newest toddler toys for Little Z to try out. In order to not overwhelm him with lights and sounds, we introduced these toys one by one over the course of a few weeks.