@swimplatypus7
So from what I gathered from how the servers work there are few things that will help you understand how things work and why they work that way.
First lets address everyones concerns that there are no players in adventure mode. We all know this isn't true, the issue is server mitigation.
A server will populate to only about maybe 3 to 4 ships before opening up another server and filling up that server and so on and so forth. Its first come first serve basically. It can go upto 6 but normally doesn't.
Why doesn't Rare just make sure that servers are always migrated and full?? - This is how it used to be in the beginning. Honestly it also seemed like the ship count was higher than 1 per outpost. I could have sworn at some points I counted 10 ships on a single server. Those were fun times.
Why did it change? - Cry babies. I say that but honestly its not their fault. PvP was pretty blood thirsty in the beginning. PvE players really couldn't do anything. Ships were attacked on SIGHT. Every quest island you went to you either had to fight a ship already there, or you had to fight a ship while you were there.
"That sounds awesome, why can't we go back to that?" - Balance. The game needs a healthy balance of both PvP and PvE. In the beginning I would have been right there with you arguing that PvP needed to be the fore front of the game. After LOTS of game time I've realized that there needs to be a healthy balance of the 2. PvE players should expect to defend themselves, but they should get chances to actually DO SOMETHING. The game was leaning to far into PvP.
"How did they fix this?" - Easy, they lowered the ship per server count to a degree. You will at times run into servers that have 5 to 6 ships in them but its uncommon for this to happen. The max count is indeed 1 ship per outpost, not counting Devil's Roar. So 6 ships max. Servers fill up to 3 to 4 ships before opening up another server. 4 ships per server isn't that high especially with how big the map is.
"But the servers look dead" - They really do. This is also because of the way Rare tries to force players out of a server. After a while the algorithm will leave a server alone and just start populating other servers. If you stay in a server long enough, you'll be the only one in that server and the game will stop trying to populate it. I think there is a Reset algorithm to when a server is open for a set amount of time its stops populating it and instead works towards getting everyone migrated so that it can reset the server. Its probably to make sure the server doesn't get any random bugs after so long.
The player base is there. Its not a question of trying to get more players to play. We have the players. They did this on purpose to mitigate PvP.
Maybe with how lucrative PvE is now, they will rethink their algorithm.
SIDE NOTE Forgot to mention the "Closed Crews" also helped kill server population. Before you would join an open crew which wasn't that bad back in the day, it actually worked because it had to. Players would be placed in servers all over the world. If there was a spot that needed filled for a crew in the UK but you were in the USA, guess what? You were moved to a UK server. So players werent really seperated by regions.
We are now though. You make a Closed Crew and you live in the East Coast, it will put you in an East Coast server. It was easier to keep ships filled and servers filled with open crews because ships wouldn't stay empty for very long. Wait 5 mins and that spot you had on your galleon is filled. So players played all over. Not anymore and open crew is troll central.