i playing sot since the open beta. the first months were awesome, each pirate would reach the legend status. i remember all people made different quests (gh,oos or merchant) or raid (only one all 2h was available). after the first became legend, the most only made legend quests becaue this quests give better loot than the normal one and in my case, this was one of the biggest mistake the devs done athena xp for non legends. which meant that you could become athena 10 without even being a legend. so at this time athena commendations weren't available and all people only want athena 10 for the clothes.
short time before the first birthday was celebrated you made a double xp/gold event. i haven't offical data, but on the discord where i'm, the number of legends has almost doubled, but the most of this people but a large part of it stopped shortly thereafter. they were legend...
and today, over the last months you implemented a lot new stuff, more random loot, event quests etc. and now the fort of the damned. if you made all the last events, you don't need to do any athena quests to reach athena 10.... and with the double xp/gold event this week faster as fast.
an other problem is, we haven't enough skins for hard commendations, for example, why should someone play a specific fraction? would be awesome you would implement a specific set ( a special "shiny" version of the existing fraction sets would be enough) for complete the fractions 100%. would give people more long time motivation i think.