When I described my experiences with the FFXIV beta, I also talked about their implementation of short, in-the-world, invasion type events (Rifts, public quests, etc.):

FFXIV adds the en-vogue public event things, were you have a marker on your map and then rush off to mash your buttons like crazy to kill stuff and get XP. Never been a big fan of those either, because it seems the best solution to large amounts of players that developers have come up with so far is scaling the HP of mobs to ridiculous levels, which makes these events tedious, but still not really a social thing, because everybody just mashes buttons and then leaves without a word after the enemy keels over.

Bhagpuss argues in a comment:

[M]y favorite innovation in MMOs of late is the huge all-pile-on fights you don’t like. I can happily mash buttons for hours in a huge crowd fighting a big monster – what’s not to like about that?

I’ll try to give my personal answer to this question in the form of a post. I’ll probably make it sound like a law of design, but I’m quite sure it isn’t. I just tried to order my thoughts into categories that make sense to me. The “why” is certainly an open question to me, and you’re welcome to point out flaws or suggest additional aspects.

I came up with three factors that make fights good for me:

1. Meaningful Interaction
2. Rhythm
3. Variation

Meaningful Interaction: I am with a group of people. We see a fearsome monster. How should we tackle it? Do I have abilities that debuff the monster in ways that increases the effectiveness of my party members? Do they have abilities that do the same for me? Part of the fun can be figuring out those combos and putting them to use. That’s a bit like using combos in card games such as Magic. This kind of interaction is meaningful because it provides fun due to interaction of mechanics. Another meaningful interaction would be outside the mechanics of the game, and purely social. It’s what old EQ players like to tell the younglings when they gather round a fire. Sitting in a location for hours and talking to each other while waiting for carefully paced respawns popping. Which leads me to the next point…

Rhythm: Good fights should provide me with a rhythm of action and downtime. That rhythm comes naturally if I am on my own and not on some sort of timed quests. I can roam around and pull mobs whenever I feel like it. I can pull them as fast or as slow as I want (provided I am careful with social or proximity aggro). It can also happen within a single longer fight, where high-DPS abilities and phases with longer cooldowns alternating with slower phases with less damage output. In a group with meaningful interactions, this can be even more pronounced by cooldown pacing of all members of the groups, stacking them or at least keeping track of other member’s abilities.

Variation: The Romans knew it already: variatio delectat. Alternating melee mobs with casters, high damage dealers with healers, and so on, provides variation that can prevent dullness. In larger and longer fights this can appear as fight phases with different tactics, or with specialized roles for players that may even be rotated among them (e.g., an ability has to be interrupted or an item interacted with every 15 seconds, but doing so gives you a 60-second cooldown).

Now, I don’t think it’s required to have all these things at the same time, all the time. But in the absence of all of them, dullness can creep in. The type of “dynamic event”/”public quest”/Rift/Fate (is there a generally-understood umbrella term for those?) I’m thinking of has none of those three, more often than not. It does not have meaningful interaction, because everybody mashes buttons as fast as possible, without any regard to other players. Rhythm is invariably off. In larger groups in Rift, most public event monsters died before I could even finish a cast as a mage. In FFXIV, we had events with single monsters that didn’t do anything but hit like a wet towel, but had the HP of an oil tanker. The fact that they didn’t do anything but hit the player at the top of the aggro list also meant that there was no variation to the fight.

I’ve seen this happen too often with dynamic events, which is why I think most of them produce bad fights and nothing good enough to offset that. They often feel like a missed opportunity. Maybe there are design decisions or limitations that make it incredibly hard to make engaging events, but the current iteration stinks.