So after reading the replies, it looks like there are two sides of this topic.
Those who wants rewards and those who believe that the surviving these fearsome beasts is a reward.
Let me tell you something lads. It is not hard to survive those beasts. I would be satisfied if it was hard. Many of you probably played Dark Souls. Now surviving a Boss in that game is a reward itself! But it also gives you extra reward which is the in game currency "souls".
Now this game is not Dark Souls but that game's risk-fun system is really well designed. And we can have such a system in Sea of Thieves as well.
Allow me to explain;
We are pirates which set sail to do certain things that allows us to make some gold. With this gold we can get beautiful cosmetics for our ship and character. And the "Goal" is to be a "Legend". Frankly speaking, I do not want to become a Legend and it couldn't be less attractive at this point.
What I love about the game is the journey! The things that could happen to me and my crew! Which brings us to the beasts, Kraken and Megalodon. Encountering such fearsome beasts should be the most troublesome and also the most rewarding moments of the game.
I know this is not a singleplayer game and we cannot give the players such awesome rewards like new ships that makes you go underwater or maybe fly i don't know don't push me...
But this game ain't giving us anything for the Kraken. Just an achievement which says "Kraken Good Job". Do you know what else gives us an achievement? Thats right eating a banana! Now I don't know about you lads but i don't thing beating the Kraken and eating a banana is on the same level of achievements.
I am not asking for the stars. I don't want to deal more damage in game or have a better armor. That will unbalance the game and no one wants that.
What @Rare-Employee 's should do is take a step back and watch us getting attacked by one of these monsters by the 5th time and see the reaction on our faces. I don't even flinch. Honestly it is such a burden and I just feel like "I really don't want to deal with you right now".
If there was something even if it was unknown, something that could come out of this fight which takes my time and resources, maybe then i would be happy to give what i have to offer. I am not even getting a calamari from defeating the so called fearsome and the most terrifying beast which is the Kraken itself.
We can have sails, figureheads, flags, titles, hats, shirts, tattoos, bite/suck marks, ship lanters that has Kraken's tentacle marks on them. Anything!
We have some of these for the Megalodon. And for which i am grateful.
But that was for the campaign! Now they are roaming the seas and i am not getting anything but my resources being used!
Even a hundred gold is something...
We can take Megalodon's eeth and sell them to any of the factions get some gold for it. We can take a limb out of the Kraken and sell it as well. Maybe add a new currency which will be earned by only killing these beasts and with that currency we can buy cosmetics that is about those beasts.
But at this point The Megalodon is the Kraken 2.0 and I am sure it will stay serving no purpose and it just feels like a cheap mod that is integrated to the game by force.