I agree. I think repetition of an activity is just artificial replayability and it hurts the game as it causes fatigue to the players.
Allow me to explain myself, in my honest opinion the Heart of Fire Tall Tales managed to improve upon what the Shores of Gold Tall Tales did. Let's ignore the journals for a moment and look at the rest of the commendations. Most of the Shores of Gold Tall Tales are done by just completing the story, but then the last one demands to be repeated five more times. Then if we look at the Heart of Fire Tall Tale we can see that the first run is not enough as there are commendations for doing the other paths, and players feel encouraged to try those alternative paths out of curiosity rather than being told to repeat it, and the two extra runs are done there by doing the extra paths. The Shores of Gold may switch the islands every now and them, but also it doesn't change much as it is the same puzzles and same battles but just in a different island, without mentioning that it's a lot of sailing while Heart of Fire has the alternatives in the same island.
Then we have the Pirate's life and Monkey Island Tall Tales, that were even bigger improvements, as those are side objectives that are not essential to complete the tall tales, but can be done out of curiosity. If done correctly, all the commendations can be done in one go, so those looking to explore every single part of the tall tale may get a total completion during the first run if they find all the secrets.
My point is that for someone like me it feels better to repeat something becauase it is my choice, rather than the commendation telling me to do it. I find it more fun to be the one choosing to repeat.
Unfortunately many commendations are just repetitions. You defeated the Gold Hoarder? Great, now do it 4 more times You cleared the Fort of the Damned? Now do it 49 more times. You managed to get a champion streak in hourglass? You have to do it 49 more times. Got a coral message and decided to sail to the other side of the map and found the breath of the sea? Now do it 29 more times. A lot of these commendations are just repeating activities, and I personally decided to ignore most of them and dedicate my time to do activities I enjoy.
Do I enjoy selling kingly loot? I do, because I can find Kingly loot with different methods (Shipwrecks, Captain skulls, Bottles), so it feels like that is done passively rather than going out of my way just to do a grind.