Having seen the story from both sides of the fence (RAF SNCO aircrew & now VR(T) officer) I can honestly say that the vast majority of the ATC staff I know are doing a great job. They give up a lot of time, put a lot of effort and enthusiasm into what they are doing...and most importantly of all, the cadets appreciate it and get something out of it.
Would you rather have your kids involved in a worthwhile activity from which they gain some discipline, experience and skills or hanging around on the streets?
Of course there are exceptions, there are obnoxious people in all walks of life, the service included.