You’re thinking about short term traders who want to accumulate more $USD. And sure, they are one actor in the bitcoin eco. Others use bitcoin as their primary currency. And still others would prefer BTC as their currency but, due to tax laws and infrastructure, are hindered from doing so.
You’re judging all current btc owners by bucketing them into one easy-to-consume cliche. Not all btc users give a shit about more fiat. Considering the buying power of fiat is a perpetual dip, it’s not exactly the best thing to accumulate.