What he meant is P2PK scripts are
Pay-to-Public-Key (
read it literally to understand 
).
You shouldn't derive the address based from that Public Key because even the owner wont be able to spend it using the "P2PKH" script even if he has the private key.
New widely used scripts are P2PKH short for
Pay-to-Public-Key-Hash which is RIPEMD160[SHA256(Public Key)],
that's where addresses work.