Can't keep things asleep in content that matters anyway since players will AoE everything for DPS efficiency or it's flatout immune making said CC completely worthless outside of PvP and dungeons in between the levels of 1-50 and 50-60. 50/60 dungeons generally giving enemies immunity to basically any real status effect.

As a BLM it's rather rare for me to pop a sleep spell...except for bad groups in Dzemael Darkhold.

Whereas for a majority of content blind effects(cue DRK/PLD/SMN/SCH) when they work aren't negated when a bum is attacked and offer more mitigation then sleep would in the long run.

Just goes to show the only viable CC in PvE is just a bunch of stuns/silences. If BLM's were given something like Breakga for petrification(which would just be an AoE stun anyway kinda like Holy but no damage) maybe we would have some nice CC utilities but then people will cry how Class A has advantage over Class B in terms of utility. Which is why you'll see NPC THM/BLM fire Breakga/Drain at you and you get stuck with a Sleep that doesn't work and....Lethargy.

Freeze doesn't even apply deep freeze. Just a sissy bind...which also in content that matters doesn't work.