Bitcoin Maximalists are the hardcore believers who think Bitcoin is the one true cryptocurrency and everything else is just a distraction or a scam. They're like the religious fundamentalists of the crypto world, preaching the gospel of BTC and dismissing all other coins as heresy.
Example
"Bitcoin Maximalists can be pretty extreme in their views, some of them won't even touch other coins or tokens."
"While Bitcoin Maximalism is a bit narrow-minded, you have to respect their conviction and loyalty to the OG cryptocurrency."