Network Technical Difficulties Caused by DDoS Attacks (Aug. 24) | The Lodestone

I’m not sure exactly what they’ve employed but the XIV team have said on multiple occasions that they’ve introduced measures. Things like that only go so far before attackers find a way around it, though.

It's also possible that other games just don't hit as often. After all, this only started as a proper problem when the first WoW->FFXIV exodus happened, and since then has cropped up every so often.

This puts some weight behind the idea that this is done by some people who are disgruntled WoW players or so. Which would also fit now, as the new expansion released and is apparently... okay, but pretty disappointing?