I think there is a basic misunderstanding here. The Bitcoin blockchain does not store public keys; it stores public key hashes.
I don't know the exact count, but early versions of bitcoin mining paid out to public keys, not hashes. I think the first 1mil or so bitcoins mined by Satoshi and a few others are not hashed and are therefore vulnerable. Plus there is not a requirement to pay to hashes, there are plenty of other public keys on the blockchain for sure.