Very interesting take on it Robin and thought provoking.
I wholeheartedly agree with some of your frustrations. people take credit for themselves for their successes, which is probably how it should be. The opposite side of this coin is that it's always 'training's' fault when no imporvements are seen
How about getting people to answer 3 or 4 simple questions instead of the usual 'happy sheet'.
1. What have you learned that's new to you?
2. What have you been reminded about that you'd forgotten?
3. How are you going to use this in the workplace?
4. How has this training/learning helped you?
The format for them answering the quesitons can be anything you want it to be but it does at least get them thinking about your input