What is wrong with missions? I take a mission, I sail to the location and I know it will be there, and I know roughly what to expect. Reliable, relatively fast way to get to the pew-pew, that's why we casuals mostly prefer it.
To hunt in the OW, you have to sail to enemy waters to find enemy AI, and in case you find a fitting enemy, engage it and hope no player comes across to help the enemy. Takes a lot of time, unreliable, and limited in enemy variety (I mostly see AI fleets consisting of 2-3 frigates, or 20 SoL-s. Not much inbetween).
Let us play our little game. What's driving you against it?