This kind of encouragement will help them focus on what they did well. Self esteem grows from honest internal improvement not external flattery. Our public schools are getting a lot of bad publicity. There are schools that have given up and may deserve the criticism. However, this negative publicity paints all schools with the same broad brush.
People become discouraged and suspicious.
They grasp at any new idea, no matter how unproved or unlikely, to try to make the schools better. You need to let people know that the children in your class are doing exciting and interesting things. I urge you to call your local newspaper and find out who the education feature writer is. Get acquainted with that person. Call him whenever you do a culminating activity.