I know absolutely nothing about hosting a site like this, how much does it actually cost? It doesn't seem like a particularly resource intensive application?
The cost might go up significantly if they're actually hosting the .torrent files. They could save space and bandwidth by only hosting the magnet links like The Pirate Bay did.
Bitcoin is pseudonymous - Transactions are transparent, yes, but the addresses are not linked to any PII - The exception comes in when the user uses a Centralised Exchange that does exactly this, it bridges anonymous addresses with PII via KYC.
Bitcoin can be sold anonymously using P2P DEXs (decentralised exchanges), where the fiat transaction has no link to Bitcoin.
That's assuming they even would want to sell.
All in all, it comes down to how the user uses the tool.
Bitcoin can be as privacy preserving as anyone wants. But if they KYC, they can kiss any privacy goodbye, and really, that's the misunderstanding that has reached most non-Bitcoin users these days. Experiences based on a lack of understanding.
Another problem with BTC is the extremely high transfer costs. Donating XMR directly makes smaller donations viable, while BTC is only attractive for large donors.