The Cultural Settlements were finite, you knew going in how many you needed to accomplish, then - Done. Yes, they were a grind, and that is all I remember hearing from users. I do not remember anyone saying it was a joy to do them or that they would love to do them forever. After each one came out, I do remember cheers of joy in Guild threads as someone finished one and received the fully upgraded building, never to have to do it ever again.
The building was a guarantee for each settlement finished. You were going to get a full level or an Emissary for each completion. There were no ‘fragments; to where you might or might not be able to get a full level as a reward for completing one. There was even a guaranteed reward for finishing in a certain time period.
.At the time, the settlement buildings were the best in the game, and well worth suffering how ever many playthroughs it was. The Yggdrasil is… err… was, 30% Attack, 8 FP, 20 Goods plus coins, medals and supplies in 9 tiles!!! You saw one in most cities!
Users did not have to do them, at all. Nothing else hinged on completing them, it is all strictly personal rewards. Some people never did them, some did all of them and some did only one or two of the settlements. Some people did one run through, said it sucked and never did another. It was a personal choice. There was also no time limit to receive the main reward. You could complete a settlement in a few days or a few years, you would get the same main reward.
Think back to what advice was given to new players: Do the Viking settlement for Yggdrasil. Now, of course, it is not an option for those new players sitting in IA learning the game and building a foundation.