For me, it's the fact there's a group of around 40 horde, give or take, literally camping the greench and AoE spamming the treats and metzen preventing any alliance from completing their daily. I don't mind some PvP action on a PvP server, but this is ridiculous.
Holiday events tend to be quite active the first couple days, but this one lasts for 2 1/2 weeks, and you can certainly complete most of these things throughout the event and have plenty of time to grab all the achievements/complete all the quests without needing to do everything the first day.
You know, normally I'd not get involved in this kind of argument, but there are a couple of points that should be made, because despite Blizzard's assertions, you increasingly can't get what you want done during certain Festivals. It's not simply the issue of individual stupid (and because Green Day didn't do a song called European Idiot I apologise to my US bretheren for the title, but I know the NPC camping isn't just going on on this side of the pond.) This is far more to do with the ridiculous nature of the RNG, and the inconsistency of Seasonal 'rewards', because when you design stuff ad hoc over the years there are ultimately shortfalls. This is by far the most compelling reason to completely upgrade Seasonal Festivals, and that it should be applied to The Timeless Isle as a matter of principle.
You see, if you work hard enough, you shouldn't have to rely on the RNG for your Battle Pet drops.
There's an achievement on the Timeless Isle for looting everything the place has to offer: Going to Need a Bigger Bag. Buying Battle Pets for this from the AH won't affect your totals, you'll need to actually win and loot every item, and that requires a number of pets whose drop rate, frankly, is stupidly low, or the mobs you need to kill to obtain them are particularly unfair in their drops. I've read of numerous people wringing their hands trying to obtain these, and I think it's high time they were made a) untradeable so they can't be sold on the AH and b) available for coins on the Island so that people who want to fight with them or collect them can do so. I know a lot of people really don't care about the achievement but simply want the pets.
The same really should be true for the Winter Veil pets. Other Festivals allow us to collect tokens to exchange for them, and frankly this should be the way for EVERY event. I don't have a problem with not making these saleable either, because I find it quite depressing that you'll see a bazillion Sinister Squashlings for sale because they drop far too frequently but people can make a killing selling Lumpy for 10k. In fact, if Blizzard could see their way clear to sorting out drop rates for a lot of pets, especially those that they've decided to have drop from Instances, that would probably be a Good Idea (TM) Yeah, I know, it's very unlikely to happen because these kind of things aren't normally fiddled with or are considered as low priority but really THIS IS STUPID.
Now, if you'll excuse me I'm going back to bed, and later on I will run eight alts through the same stupid daily quest in the vain hope the RNG will gift me with a Rotten Helper, and I can help supply Guildies with the Lumpy that has, for many of them failed to drop since it's introduction.
There ARE better ways, and the game ALREADY USES THEM. Please introduce more consistency.