Since 99% of the posts here are 100% subjective (which, is fine, we're all entitled to our opinions - but that's just what they are, opinions) I'll add mine:

Game released with spell casting while moving... I thought it was "alien" to me, but of course I adapted and I got used to it.

1.21 came out and removed spell casting while moving... I thought it was "alien" at first, but again I got used to it.

As a WHM I can only not heal someone if they decide to go all "Dora the Explora" on my and run way out of my range for w/e ADHD reason they have. Same with on PLD - whether kiting or not, I can heal myself (and others just fine - unless they fall into the "Dora" category).

Basically, 1.21 helped me realize that casting while running around like I'm on fire was really just a crutch for players who couldn't stand still for 4 seconds to cast a spell. Now, after 1.21, and using /facetarget in all my macros, I can run around to avoid any AoE/ground mechanics all while being able to quickly stop to cast without getting interrupted.

Less "easy mode" - I like it. Keep it up Yoshida and the dev teams! I look forward to more of it in the future!