Most people just abandoned Bitcoin when the price is very very low. They don't even think that the price can surge and hit $100.000 because they think that is impossible. But then when the price slowly increase and hit many new ATH, they will start pay attention to Bitcoin although they still not trying to buy and hold Bitcoin.
They don't think to use Bitcoin as their investment because they are still prefer with their current investment such as gold and others. Or they don't want to open their minds to see the other opportunity to become rich in the future.
That's why knowledge and consistency in investing in Bitcoin are important, because many people who enter Bitcoin invest by just following other people, they don't understand Bitcoin's volatility and its potential in the future - even many invest like gambling/trading. Because if they understand how to invest properly in Bitcoin, they will not be affected by the market, and will continue to regularly invest in Bitcoin at any price using their discretionary income or money they are ready to invest, and hold it even more than 1-2 cycles until they can get a decent profit from it.