Just because both of them have high correlation, that doesn't mean Bitcoin price isn't affected by S&P 500 price. It's more likely both of them affected by global event 
For years people in this community were telling that Bitcoin is new gold, that it's a hedge against wars, economic crashes and all the other disasters, and people really liked to post negative world news, implying that it's bullish for Bitcoin. Covid-19 crisis was the first real test for Bitcoin, and by some marks Bitcoin failed it - it crashed together with stocks and other markets, showing that it doesn't have these hedge properties. This is the real problem here, at least to people who justified their hodling with those ideas.