If the dive lasts more than (X seconds) the turret would charge a 2nd laser and the damage increases. Would be a really cool feature to add and would probably solve any 1 minute diving problems. Either that or Riot's balance team comes up with a genius solution which is nerfing them.- Typical balance team ...
As I wasn't playing back when they used lasers, this will be quite hard for me to answer, but I'll try anyway.
Essentially the crucial thin to know is that towers are only really useful in the early to mid game, and personally I think that it's very useful. In early game especially using turrets can help you dispose of over extending Laners and particularly aggressive junglers, although, as you said, there are situations in which champions such as CAMILLE, JAX, YASUO and FIZZ can dive in and out without taking lethal damage. This may seem frustrating when you are on the receiving end of a dive but I find it way more frustrating when you get a champion really low and they run under their turret and recall, wasting effort and sometimes mana too.
In your remark about RIOT nerfing I can't figure out whether you want to nerf the divers or the towers, personally I find that nerfing the towers to be out of the question, they are already ineffective in late game or against tanky Laners like MALPHITE. Nerfing the diving champions is the better idea as it would balance out the huge assassin meta currently going on. Yasuo already is about to be nerfed/reworked and so it's actually already started, hope his helps!
