There is a wide spectrum of ability and interest (and the ages go from perhaps 8 or 9 to mid teens), but a large proportion of the kids get it and are off and happily programming away to make their flappy bird clone based on some basic instructions. Many say they already know Scratch from school. Many get bored and go rogue by ignoring the instructions and doing their own thing with the game and you start to see some bizarre mashups of what they're supposed to be making and what their imagination came up with. When we run those classes, the feedback is usually really really positive.
Sure - scratch is not "programming" as most of us would think of it, but it is programming.
Tl;Dr - give kids a break. There is interest and ability there if you give them the chance to express it.
It is very easy to judge.