I really have mixed feelings about this.
On the one hand, I almost never get hit by WotL in Titan unless I space out and forget it's coming. This means I need to memorize every ability he has. This is easy, and does take some skill, because you need to know what's coming ahead of time. Once people memorize when weights are coming and get out of the mentality that they have to wait to see it before they move, the fight becomes 10x easier. Before everyone started learning the pattern, I used to announce when weights were coming on voice chat so people could move ahead of time.
Why is this necessary? Because there is lag and obvious positioning issues. I don't complain about it because EVERY move is predictable and you can plan for it ahead of time. Even Coil is predictable for the group. ADS has a rotation that never changes, so even if you are lagging in Coil (it's notoriously laggy in there), you can move when you know you need to move and never get hit.
Moving ahead of time is a work-around, not a fix. We can still beat these fights, and I am proud to say I can, but I do not believe I am beating it 'as intended'. However, I do believe that the fights were given PREDICTABLE patterns to cater to people who ARE lagging.
A good example of the differences between ARR and 1.0 would be Ifrit Extreme. There was a loose pattern as far as when certain abilities MIGHT come, but it was not completely predictable. If you were lagging and Ifrit decided to dash when you were in a bad spot, you were dead. Your teammates would see your body slide across the floor in a notoriously unfair fashion. Many people could not beat this fight SIMPLY because of lag. Lots of people died -- people popped the Grand Company raises like they were candy in this fight.
Square Enix's response to this problem in ARR is to introduce incredibly predictable fights... or at least, predictable when it matters (for the whole group). It works, but a lot of players are STILL playing like they should be able to see something and THEN move. This isn't going to work, unfortunately, even though it works really well in other MMOs. The FFXIV engine just isn't optimized for it. I could give the OP a number of ways to 'work around' the positioning issues... such as using an ability the second you are out of an AoE (it force-updates your positioning), but I do think the positioning issues in this game should be addressed if fights with UNPREDICTABLE rotations (such as extreme version primals) are to be released... and don't even get me started on how bad PvP might be if this 'natural position lag' stays. =/
P.S. For people who are avoiding weights without moving ahead of time... good for you, and I mean that sincerely. I am happy that you can wait until you see them because it means your game is updating faster. Whether it be ISP lag, hardware lag, or just natural latency from being far away... a lot of people are having this issue. Not just a few people. A lot. The game needs to be accessible for everyone, and other MMOs manage to pull this off. I hope the FFXIV servers are optimized at some point... I know reworking them right now isn't top on the list since they have to push out more content, but I do hope it's addressed eventually.