There are approximately a fixed number of shares out there for a company. When you say investors moved on, that's not exactly true; somebody bought those shares. Somebody took the losses as AOL declined. And although some investors surely were happy to move on, they would surely would have been happier if the stock kept doing well, if they didn't have to move on.

Good investors diversify. It's possible that people who invested in AOL wanted them to keep the same business model and not try anything new, because they also invested in the other companies that were trying the new things.