I have spoken to a number of people that have attended Speed Awareness courses, some say they were bored and they were a waste of time others say they were very enlightening and gained alot from them. I know who I would rather passenger with !
I have to say I found mine really quite enlightening. Clearly I didn't learn enough though, as I've done two in the last 15 years or so
But yes, the idea that they are useless and one can learn nothing from them is clearly indicative of a type of driver it would be well to keep well clear of.