Is only an immature trader that sees bull times as the only or appropriate time to make profit in trade. A good trader makes profit even in bear market. He/she milks the market at anytime he is convinced for a trade.
I've known traders who only trade bull markets because it works best for their trading style. If your trading system doesn't perform well in bear markets, you should act accordingly and seek out bullish markets to trade.
When it comes to crypto, I definitely prefer bull markets because there are so many more opportunities. Alts will eventually pick up and we'll start seeing 10x moves everywhere you look. A bull market also means I can hold spot coins in my own wallet rather than constantly trying to hedge short or sell coins + hold USD on exchanges. Less exchange risk this way.