Going to put this out there: lag is a real problem on Titan. I don't think it is network lag either, in fact I think it is more of a drawing lag (so low end vs high end hardware). It does exist and I have been hit by it really hard in Titan, more than once. And then in other fights I don't see it at all. If you had ever experienced it for yourself, you wouldn't put it up to an excuse by bad players. The difference between the titan lag and other dungeon lag is just extremely ridiculous. Even knowing the fight I can usually tell within 50 seconds if I am going to have lag problems, or someone else is, and it is more along the lines of having to move 2-3 seconds before you think you need to and hope you have the pattern perfect.
This isn't to discount the possibility that some people are using it as an excuse even though they don't have it, but the problem does exist and is a very real problem, and definitely falls into OP's first category. I don't think there are as many major issues as other people do, but there are always some issues with every game, including this one. In my experience the bigger issue is definitely category 2: the attitude of the people who are unforgiving of error, and unwilling to accept sometimes the problem is outside the control of the player, and further are unwilling in either case to work through the issues be it player skill, or game bug, or network lag. I am not sure about the 2.5gcd being a problem per-se, though many people don't understand how to work within it, especially those things that trigger on server time, not client time.
Anyway, I am not so great at in dungeon communication, but I try, and am willing to keep going right through to the end, unless others aren't and there isn't time to finish. Even if there isn't time to finish I will keep going for the sake of other players so they can have more chances to learn the fight if they want. It is what I personally would want, and do unto others etc.![]()