Why are Turrets so pathetic?

The new turrets are ridiculously weak. When I had read about the new changes, I had thought Turrets to be harder to kill off but it's so weak it's weak.

Outer turrets are fine, usually dies early game and instantly late game, completely fine.

Inner Turret shields are just crap. They're "late game" turrets yet so weak. Inners are prone to minions mobs more than ever since they got "buffed" and the fact that the shield only takes damage from champions in non sense, the shield is way too squishy.

The only times when it's useful is when the enemy all push together so the shield is crap and if Tryn or some split-push champions goes in, also crap. It's a well known fact that inners are prone to one swarm taking one from full health to 0 so the shield it's completely crap because nobody bothers with split pushing too too much or shreds it.

Nexus turrets are too weak for end-game.

Lasers are pathetic because minions die too fast for it to charge and quick dives make laser charging impossible.

The minion health scaling is also ridiculous.