The video is informative , short and succinct! I think its going to be quite difficult to retain the dollar sign representing the actual value soon. I still fear that in the long run, it is not better to just reward people as much actual value they bring to the site and pay a percentage slice from that added value?

At the moment, the value of an author reward is roughly 1/3rd of the displayed dollar amount.
(Post Value x 75% )/2 = SBD payout
The other half is paid in STEEM power which is essentially locked up for 2 years.

The fallacy here is that the steem power paid out is quoted in dollar value when it is almost impossible to ascertain what value steem is going to have 2 years from now. A more accurate calculation of steem power shouldn't be "The value of steem power if it were converted to dollars on the fly at today's prices of steem / btc" because the nature of this particular asset is such that there is a maturity date set some what far in the future.
In that case, we can only extrapolate and speculate what the value of steem may be 2 years later.

TLDR; Steem power should not be counted towards to the dollar value payout of the reward. Dollar rewards should be adjusted to just SBD / SP because pegging the price of the dollar gives unrealistic notions of how much reward is being handed out vs how much a person actually receives.