It prompts very different behavior, to extend the coin flip metaphor: If you could slow down time and see the flip turning bad, you could quickly withdraw your bet. Then you'd be much more likely to bet a higher fraction.
I was thinking about this while reading. The Dot Com and Sub Prime mortgage crashes took a lot of people buy surprise, but not everyone. Moving into T-bills, cash, or precious metals at the beginning of those downturns would be enough to make the 2x Kelly and 3x Kelly perform better.