What does it usually mean is wrong when oil shoots up the motor out of spark plugs and coats entire engine in oil?

Excessive oil pressure: If the oil pressure in the engine is too high, it can cause oil to be forced past the spark plugs and coat the engine. This can be caused by a faulty oil pressure regulator or a blocked oil filter.

Worn piston rings: The piston rings help to seal the combustion chamber and prevent oil from leaking into the cylinder. If the piston rings are worn, they can no longer effectively seal the combustion chamber, which can allow oil to leak into the cylinder and be forced out through the spark plugs.

Damaged cylinder head gasket: The cylinder head gasket seals the cylinder head to the engine block and prevents oil from leaking between the two. If the cylinder head gasket is damaged, it can allow oil to leak into the combustion chamber and be forced out through the spark plugs.

Improperly installed spark plugs: If the spark plugs are not installed properly, they may not be able to effectively seal the combustion chamber, which can allow oil to leak into the cylinder and be forced out through the spark plugs.