There's a thread on the Guild Wars 2 Reddit currently that asks why non-wvwers don't wvw. It's a gold mine of useful feedback not only for Arenanet, but also for everyone who makes up the wvw community.
One of the themes I keep seeing (and this will not surprise you) is that people have no idea what to do. They don't understand the scoring, don't understand how they may contribute to the scoring and don't know where to find the action.
Part of this problem can only be solved by Anet. If memory serves, sPvP gets a much more detailed introduction than WvW. I went into it knowing exactly what to do and what actions to take to create desirable results. It was just a matter of whether or not I could pull it off. On Anet's side, they have made some improvements like showing how many points some things generate if you're in the area. If someone plays for a long time, they can likely figure out the basics. Unfortunately, they don't tell people this upfront. On ABL/EBG, there's an NPC that gives you an overview of some game aspects. On DBL, at the time I last entered the Citadel, no such NPC existed. If anyone is on Red team currently, can you let me know if it was ever added? Update: Confirmed no Tutorial Instructor in RBL Citadel.
The ABL/EBG Tutorial says that towers allow you to control the roads and can be used as a base of operations. The former concept was stressed in DBL while the latter was stressed in ABL. The Instructor later says that Keeps require a significant and sustained effort to take. Thus suggests that Anet at least initially thought sieges wouldn't just be a single zerg push. However, while the tutorial has been updated to reflect the new point values of objectives, it makes no mention of increasing point values when they upgrade. In fact, it makes no mention of structure upgrades at all.
Perhaps to make things more interesting and more informative, allow for an optional, instanced tutorial where a player must:
-Capture a camp.
-Grab 10 supply from the camp.
-Walk to a nearby tower and place the final 10 supply into a siege engine.
-Finish off a low-health wall/gate.
-Fight the tower lord with NPC allies.
As a continuation or a separate instance, a player can:
-Escort the final Yak to a tower to upgrade it from tier 1 to tier 2. Emphasize the visual change in the walls.
-Defend the tower from an enemy catapult either by running out and blowing it up or by using a counter treb.
-Failing that, defend the tower lord by killing all enemies.
-Spend 10 supply repairing the tower's wall.
Tutorials like that would ensure that people would at least have the basic idea of how to do things. In practice, they'd know what actions to take. It would just be a matter of if they could pull it off with other players taking opposite actions.
There also needs to be a more extensive 'You Won!' celebration. Even if it was as simple as a Special Skirmish chest for any Skirmish where you spent 10+ minutes at tier 1+ activity. The rewards would be based on where your server placed, perhaps, and a semi-big deal would be made of it when you click the chest (not immediately upon receipt as that could interrupt gameplay). This should help give people some idea of what they're fighting for. Also, as a replacement for the old PvE bonuses, perhaps give personal or guild PvE buffs based on server placement and player contribution?
On the other hand, WvW players usually just say to follow a tag. The newbs dutifully follow a tag (if one exists) and are chastised for their build/class choices and total lack of large combat instincts. If this doesn't cause them to quit, they go on to stomp/get stomped in zerg battles and eventually leave without much idea of what just happened. If they don't leave the game mode completely, they still have no clue what to do if there is no tag and lack the confidence to take any sort of initiative.
Following a tag is nice, but it's not a great first step. It would be better for everyone involved if players first had a reason to want to win, then got on tag. They would be more motivated to improve. Right now, the players who fight for the sake of fights tend to adjust well, join a fighting guild, then lament that WvW isn't just all zerg fights all the time. Players who aren't super stoked about large scale combat tend to abandon the game mode entirely.