I remember using it back on the old chain, and I'd show it to new users to give them a visual idea of how stake increases over time. When it went away, I asked Matt if he minded if I revived it. I added a few decimal points to the HP so that even people with really low stake could still see it growing.
Surprisingly, it really helps it to click with people who aren't getting it!
I agree. It's a perfect exemplification of how HP "interest" works, since no visible traces for the regular users are left on chain to see it in action.