So you're basically complaining that you died because you got punished for doing a skill at the wrong time, ignoring the dangers of the enemy? If you should have time to use an ability "but don't because you're rooted for 10 years", then you obviously don't have time to begin with. Animation lock was not the problem, the extremely long animations themselves were the problem. SE made the boss mechanics faster, while not doing the same for players. Bosses themselves were rooted when doing their animations, so it's not like it was completely one sided either. The fact that more action packed games, with faster gameplay, do fine with animation locks is proof that how SE went about their game in 1.0 was plagued with issues.
Your understanding of animation locks in fighting games is also lacking. Each move has a certain length where you are punishable and where you are safe. Doing a roundhouse kick at the wrong time is just going to get a fist to your face but doing a jab will leave you safe if done at the proper distance and even bait the enemy to try and punish you which in turns means you can punish his counter. Countless fighting games leave you completely open when you do a special move at the wrong time, even fast paced games like MvC2 and MvC3. Just blindly throwing a fireball and whiffing can lead to a phat combo that takes half your life. There are other mechanics in fighting games that don't exist in FFXIV, like canceling one move into another, which honestly, would have benefited all the QQing about "I got hit by cracks cause I was Doom Spiking like a derp!".
That aside, the new battle system we are getting is just a different animal. Since we no longer will be completely rooted when doing a move, battle pace will be different. Whether it's better or not is opinion and perception much like someone who prefers Rugby to Football. The lack of animation locks though means that mages will definitley need instant cast skills for PvP if melee can just attack and advance at will, especially considering mages are "rooted" when casting a spell since movement cancels their damage potential.