Trends you discribe are nothing outstanding in given conditions. While market tanks, smaller coins tank even harder. During last bear barket BTC lost roughly 80% of its price, at this time most of altcoins dropped by 95% and more. This is asimple risk management by investors.
Obviously HBD rewards come from inflation, but you missed the point, HBD interest is a drop in the ocean while compared to author rewards, hence irrelevant and your theory doesn't stand in the light of these facts.
HE tokens are extremely nieché and risky investment for a long term. It's no surprise these might tank even harder.