Conrad,
The AIMer is also selling while the B&Her is not.
So when doubling the stock price, the B&Her is ahead more than a factor 2. Up to this point the B&Her is the better investor.
Then we return to the mean, which is a law of nature. Here the strategy of the B&Her is exposed because for this part of the cycle her strategy is flawed.(She should have sold at the top). Of course a B&Her can add here other strategies.
Agreeing with your observations, K