There's a userspace implementation you can use if you want.

Not doubting you, but ignorant and curious. What’s the security benefit of userspace?

Easier to introspect/update/verify?

If the kernel code is vulnerable then the attacker gets full control over your system. They can also easily hide their presence. If the code is in userspace, the attacker won't even be able to read your files if you run the daemon under a separate user account. They only will be able to mine Bitcoins or use your computer as a proxy for a short time.

You won't get access to kernel memory space (I think).