Because there is a small group of people that care enough to use it. Most anti-crypto people do not want anything to do with it. Neutral-crypto people don't see the reason for enhanced privacy, or are afraid it might put them into trouble with regulators.
Pro-crypto people can be broken into different tribes. Bitcoin maxis feel that only Bitcoin is worth using, and they might think the privacy of Bitcoin is "good enough." Ethereum maxis want to use applications and smart contracts for DeFi, escrow, exchanges, lending, stablecoins, and Monero does not support that. Ethereum maxis also feel that privacy is solvable with ZK proofs and private rollups. Then there are other tribes like Solana users who are looking for scalability for games and apps, and don't care as much about privacy.
Pro-crypto people can be broken into different tribes. Bitcoin maxis feel that only Bitcoin is worth using, and they might think the privacy of Bitcoin is "good enough." Ethereum maxis want to use applications and smart contracts for DeFi, escrow, exchanges, lending, stablecoins, and Monero does not support that. Ethereum maxis also feel that privacy is solvable with ZK proofs and private rollups. Then there are other tribes like Solana users who are looking for scalability for games and apps, and don't care as much about privacy.