imagine if you're an ad champ, no magic damage suddenly someone like yi, or vayne sprints at you full force with morgana's E on them, how do you kill them if hard cc is their main counter?
When your playing against morg + any champ whose main counter is hard cc, dont put yourself in a fight or die position while the ability is up. If you cant safely escape from the
"cc - imune" carry, it means that you probably overextended or overstayed.
Morg isnt a popular support anymore since she is so easy to abuse. Most cc abilities can be used more than once in the time it takes for her shield to come back off of cooldown, which means that you can bait out her shield with some cc and then take advantage of the time where her shield is still on CD but your cc isnt (its usually a pretty decent window of time). If you dont want to feel like your wasting your cc, you can get creative and find other ways to bait out the shield that wont cost you anything.
Example:
both come to an abrupt stop while casting their hooks. If you really want to play mind games, try running straight at the enemy and then as soon as you are in range to hook them, press the "stop movement" key (usually s). If they are afraid of getting hooked, you'll likely scare them into using their spellshield (applies to
and a few other champs too). If you do it a bunch and they catch on, you wont be able to bait it out of them anymore, but they'll have a lot slower reflexes when it comes to using the shield from that point on, so really its a win win situation.
Basically the key to playing against Morg is to get the shield on cooldown in advance, have a enough magic damage to get through it, or dont overextend while it is available.