It depends on how you define it. It was a term Vitalik made to make fun of us that got reclaimed. Some people may define it differently. Can you be a maxi and like... STX? RGB? RSK? Counterparty? Liquid? TARO? OMNI? USDT? Fedimint?Swan Bitcoin? Guns N Bitcoin Conference? Strike? Everything listed there has a degree of straying from the purists.
People usually go through a phase of "Bitcoin is the only one that will succeed, but I can end up with more Bitcoin in the long run if I do x, y, and z, in the short run." Some people that only held BTC got Celsius-d from this behavior. Trading generally causes people to lose money. But I feel that Maxis are against it for a different reason; they see it as immoral. It's as if Bitcoin Maximalism not only relies on a set of expectations about Bitcoin's future, but a set of rules and behaviors. If these moral guidelines were not a part of the definition, people that make their own scammy crypto projects could be considered closet maxis, they just have found out a really effective way to stack a lot of Bitcoin with.