Shield spamming is a problem, but the shields themselves are only part of the problem.
Every single shield that can target allies also has some additional effect attached to it that either buffs the person receiving the shield or better enables the shielder to peel for their ally.
shield slows.
shields gives AD.
gives MS.
moves Lee to the target, allowing him to kick you away.
gives on hit damage.
is AOE and can be applied twice.
gives CC immunity.
gives resistances.
moves Rakan to the target so he can CC lock you.
teleports him across the entire map so he can CC you.
heals you.
gives you armor.
repositions or saves from getting caught.
slows.
And with the availability of CDR and Windspeakers, shields are completely out of control, and yet Riot still refuses to give us counterbuild options to deal with them. It's time. 45% CDR shield spamming with Windspeakers needs a counter.