Do you have some examples? I think the most valuable criticism is that which comes with some ideas for improvement, which it is difficult for people who don't know how the thing they're criticizing works to give. In my experience, the criticism of the non-experts that you're lauding, most often points out things that the experts already know about, but simply haven't been able to solve. In general, I think identifying problems is the easy part, and that good ideas for solutions is where the value is.