USD is itself a depreciating asset. In theory, over the long term, one would expect solid cryptoassets to rise in value against USD by default. Having token value in BTC would give a good view of the strength of the token within the cryptoasset marketplace as a whole. Performance against BTC is the performance we want to see.
Plus, when I take profits, I want to take it into BTC as well as USD.
On the website, there could be a switch (like light/dark mode) from USD (fiat) to BTC (crypto).