More Summarising and New Points
@Zeddicus2017 and @Vorlon make interesting points: for them, the World Event alone is not enough to do in the game. Presumably that applies to every week now. In that sense, Guild Wars is the extra event that gives them something more to do over a normal week.
Personally, I would say: you can always do more PvP or Explore (though Explore is pretty boring and effortful now, as I’ve discussed elsewhere).
The “Play all Events” Assumption
I erroneously assumed that all players will try to do all events to the best of their ability. I don’t mean doing their best to maximise their score in Guild Wars, for example (though serious players will definitely do that, and spend many hours on it, as pointed out). I just mean that most players will try to “finish” every event – at least to try and use all their free Sigils/Battles.
Apparently this is not true for a substantial number of players.
Who is the Target Market?
The question then becomes, who are you catering for?
I would argue that you should primarily cater for those people most likely to spend resources in the game (not necessarily money, though one does imply the other, within the limits of individual budgets). As @awryan points out, the people who have been in the game a long time and are seriously invested in it (emotionally more than monetarily) are a critical part of the player base. In large part, that’s because they have the most influence over other players, both current and future.
It’s also important to note that people who want more to do in the game are likely to be very much in the minority. Except insofar as it makes sense to make the infinite-play aspects of the game as engaging as you can (Explore really does need improvement).
You also can’t target people who barely play at all. Yes, it’s important to give them interesting things to do so they don’t stop playing entirely, but you can’t weight their opinions equally with more serious players.
It seems logical, then, to weight players’ opinions not just by how many fall into each category, but to multiply that by the amout they play. So the opinions of people who play a lot are worth more than those who play the average amount (and incidentally, more than those of the devs – at least in terms of evaluating the play experience – who honestly don’t play much at all).
A Modified Assertion
If the developers consider a World Event to be the right balance of play time during a week (in addition to all the daily and weekend events), then they must necessarily concede that running Guild Wars and the World Event concurrently is far too much, and is a critical mistake, because I’ve shown numerically that for the vast majority of players Guild Wars takes at least as long as the World Event to complete.
This is irrespective of how seriously you play Guild Wars. If you do it at all, it takes about the same length of time as the World Event.
Keeping Players Engaged
The other thing that’s critical for player retention and emotional investment is to remove obstacles and frustrations. That includes improving the interface, rebalancing (at times), and making sure players are not over-whelmed at their personal level of commitment to completing events and advancing through the game.
Nearly all free-to-play developers are good at focussing on pulling people into their game. The next stage is to psychologically manipulate people into paying money on a regular basis (this is the unethical, but normalised, “artificial grind” that can be eased with money).
But the other side of the equation is usually ignored. Namely, it’s always a balance between what pulls you into the game and the obstacles/annoyances that push you away from the game. Ignore the latter at your peril!