So riot saw the state of turrents and went "you know, we should make them weaker"
With all the complaints about champions in the last couple patches I feel like this almost slipped through the cracks. Next patch the inner turrets are losing more than three quarters of it's shield (200 -> 30, but gaining health) and losing the ability to shield champs if the tower has it's shield down. (Edit: to clarify, it seemed like right now if the shield went down, your shield didn't disappear instantly to me, but I knew it didn't give you any more shield once the turret's went down, and it sounded like that was changing to instant loss as soon as the turret takes a single hit and drops shield)
The front towers seem to be increasingly weak as champ protection in the early game (more champs diving earlier, Tristana's E can punish you for tower hugging, etc.), and the inhib and nexus turrets are almost useless if anyone gets to them with even a single wave due to wind up damage, and tanks/tanky fighters can rip through them earlier with an ADC, the inner turrets were about the only things left that felt like it was hard to take, and valuable to defend and now they're gonna be weak like the others.
). By the time late game rolls around, normal turrets tickle at best anyways, even on the squishiest of carries. I think the only change the beam turrets need are increased regeneration.