Yes, that discounting makes sense, but it's explicitly not what Eliezer is talking about. His very first sentence:

"I've never been a fan of the notion that we should (normatively) have a discount rate in our pure preferences - as opposed to a pseudo-discount rate arising from monetary inflation, or from opportunity costs of other investments, or from various probabilistic catastrophes that destroy resources or consumers."

(Also, I don't see how that example is 'hyperbolic'.)